NGC 1. See NGC 7839.
=====
NGC 2. See NGC 7839.
=====
NGC 3. See NGC 4 and NGC 7830.
=====
NGC 4. This really is the very faint galaxy about an arcminute south of
Marth's position. He was observing with a 48-inch reflector, the second
largest telescope in the world at the time, so he really could see very faint
objects like this.
LEDA took NPM1G +07.0004 as NGC 4. This is brighter, yes, but it is nearly
21 arcmin away from Marth's position, and by random numbers in both RA and Dec
(52 seconds of time, and 16.5 arcmin). No digit errors there.
Also, Marth's relative position from NGC 3 pins this object down. He found
both on the same night in November of 1864, so the telescope was zeroed the
same for both galaxies. Marth's offset from NGC 3 to NGC 4 is just 10 seconds
in RA and 5 arcmin in Dec. The offsets from modern positions are 7.6 seconds
in RA and 4 arcmin 20 arcsec in Dec. This is well within the errors of
Marth's usual accuracy, so the identification is secure.
Also see NGC 7830, another very faint object that Marth found the same night.
The total V magnitude of NGC 4 (around V = 15.5) bears on the identification
of NGC 7830.
=====
NGC 6 = NGC 20. On the night of 20 September 1885, Lewis Swift found six
objects. Four of these (NGC 19, NGC 21, NGC 7831, and NGC 7836; see the notes
for these, too) have mean offsets in their positions as published by Swift,
from the correct positions, of -1m 10s in RA and -8m 08s in Dec. A fifth
found later in the night, NGC 801, has offsets of +19s and +0.9m; Swift
clearly "re-zeroed" his telescope in the interim.
The sixth object, NGC 6, shares the right ascension offsets of the first four,
but its declination is about 45 arcmin too small. Its identity with NGC 20
is secured by Swift's note "... one of 5 sts which point to it is pretty
near." The unmistakeable line of five stars stretches about 2 arcmin to the
east; Swift's "pretty near" star is about 15 arcsec east of the galaxy.
=====
NGC 8 is a double star about 3 arcmin northwest of NGC 9. Both objects were
found by Otto Sturve in September 1865, NGC 9 on the 27th, and NGC 8 on the
29th. Struve's relative positions for the two are good, though his absolute
positions are -12 sec and -2 arcmin off. His measurement of the 10th mag star
about 6 arcmin east-southeast of NGC 9, however, clearly identifies the two
objects he saw.
=====
NGC 9 is a peculiar spiral with a bright blue patch on its southern arm, found
by Otto Struve. Though Struve's position is about 3 arcmin off, his
measurement of the star 6 arcmin east of the galaxy insures the
identification. See NGC 8 for more on Struve's observations.
This galaxy may be a ring galaxy similar to NGC 985, though seen almost
edge-on. The SDSS image (see e.g. Courtney Seligman's pages) doesn't conflict
with this idea, though my initial thought that the blue knot on the southern
side is an interacting companion now seems far less likely.
=====
NGC 14. See NGC 7555.
=====
NGC 16 = H IV 15 = h 4 = h 5. Here is a peculiar case where both WH and JH
have enough problems in their observations that Wolfgang Steinicke has
suggested that JH actually saw NGC 22 in one of his observations rather than
the much brighter galaxy that his father found. Courtney Seligman brought
this to my attention in April 2015; see his web page on the object for his
take on the problems.
WH first saw this on 8 September 1784 and put it 2 minutes 6 seconds east of,
and 1 degree 21 arcminutes south of alpha Andromedae. There is nothing there.
But about 1 minute and 24 seconds west is found a galaxy more or less matching
his description in CH's fair copy: "Stellar, or rather like a faint star with
a small chevelure and two burs [sic]. F, S." There are a couple of
additional things to note. First, there is another star in the sweep, 85
Pegasi that gives a different RA zero point. Using that, the position for
WH's object becomes just 1 minute 6 seconds west of the galaxy. This is
strongly suggestive of a simple digit error in WH's observation.
The next observation was by JH on 5 September 1828. This pinned down the
galaxy very well, but JH added a note in parentheses to his observation, "(?
[query] if not IV 15)", well aware that his position was well off his
father's.
JH went over the field again on 16 September of the same year, but recorded
only an approximate position for the object, calling it "A star 15m with a
burr AR [sic] from Cat." So, he accepted that he had seen the same object
in this sweep that his father had, even to the extent of adopting the RA from
his father's list. There is, of course, nothing in this position.
And this is where the trouble really sets in. JH enters the two observations
in his own 1833 list as two separate objects, and copies both into the GC.
d'A comments that he cannot find GC 12 = h 5 on three of the five nights that
he observed an object which he called H IV 15 = h 4, not following JH's own
list where he (JH) put IV 15 = h 5. JH has a rather peeved note in GC about
this: "D'Arrest says, 'h. II. positio cert erronea,' but gives no indication
of the correction required in R.A. or P.D."
Dreyer finally sorts it all out for the NGC by making IV 15 = h 4 = h 5,
adopting something of a mean of JH's and d'A's positions, and adding a note,
"h 5 was not seen by d'A [3 nights] and St[ephan] (XIII) [2 nights]; it is
= h 4 as they were observed in different sweeps." In his 1912 edition of WH's
complete scientific papers, he adds "IV 15 is = h 4, 1m 20s p[receding] H's
place. Some error in recording the transit, probably of 1m; reductions
correct."
So there matters stood until Wolfgang went over the field during his
re-evaluation of WH's observations and decided that IV 15 = NGC 22. He also,
in his re-evaluation of JH's observations, has h 5 identical to a star at
00 10 28.0, +27 42 00 (there are neither stars nor galaxies there). I have
not yet had any correspondence with him about this; but given that WH's
declination is off NGC 22 by 7 arcmin, and that a simple 1 minute of time RA
error will explain the difference in position with NGC 16 -- well, I find
myself agreeing with Dreyer on this one.
=====
NGC 17 = NGC 34. This galaxy is clearly identified by its discovers' (Muller
and Swift) descriptions of nearby stars, in particular the double star two
arcmin west-northwest. Along with many other of the Leander McCormick
nebulae, its approximate position is about 2 minutes of time too far east.
Herbert Howe was the first to suggest the identity, again based on the clear
descriptions of the double star, which he observed just where Muller and Swift
claimed it to be.
=====
NGC 18 is a double star 4 arcmin east of NGC 16. It was found by Herman
Schultz whose micrometric position, measured on two nights, is within 3 arcsec
of the GSC position. Dreyer notes that N18 was not seen by either d'Arrest or
by Lord Rosse.
=====
NGC 19. As with NGC 6 (which see), NGC 19 is unambiguously identified by
Swift's note about the surrounding star field: "... in center of 3 very faint
stars forming an equilateral triangle, two of them double." The double stars
are northwest and southwest of the galaxy, with the third star being east-
southeast. Swift's position for the galaxy also shares the systematic offset
of NGC 21, NGC 7831, and NGC 7836 from the true position.
Concidentally, Swift's position for NGC 21 (which see), while closer to
NGC 20 (as pointed out by Courtney Seligman), has been mistakenly applied to
NGC 19 in RNGC, UGC, and UZC.
=====
NGC 20 is also = NGC 6 (which see). NGC 20's original NGC position is
correct.
=====
NGC 21 = NGC 29. Though Swift makes no comment about the surrounding star
field, the identity of his object with Herschel's is clinched by the offset of
his (Swift's) position from the true position: NGC 19, 7831, and 7836 share
the same offset (see NGC 6 for more information). The NGC position for NGC 29
is correct.
=====
NGC 22 was found by Stephan in August or September of 1883. He measured it
micrometrically, so his position is good.
However, it is not, as Wolfgang has suggested, H IV 15. See NGC 16 for that
story.
=====
NGC 28 and NGC 31. Found by John Herschel during his stay at Cape Town in the
mid-1830's, the identifications of these two galaxies are unequivocal. This
has not prevented PGC from equivocating: it claims that the SGC
identifications are wrong. Balderdash and bull feathers!
Unfortunately, ESO missed the galaxies (and NGC 37 as well), so that NGC 28 is
not even in ESO. ESO 149-G020 is NGC 31, and ESO 149-G022 is NGC 37. All
this is probably why the PGC folks were misled. The PGC error also crept over
into RC3; the galaxy identified there as NGC 28 is actually NGC 31.
=====
NGC 29. See NGC 21.
=====
NGC 30 is a double star. This was recorded only once by Marth in late 1864 as
a "nebulous star 13th magnitude." There are no galaxies within 10 arcmin of
Marth's position, but the double star is within an arcmin. On a night of less
than perfect seeing, it would probably appear as Marth described it.
=====
NGC 31. See NGC 28.
=====
NGC 32 is apparently the northeastern of a pair of stars separated by about 30
arcsec. It was found by Julius Schmidt on 10 Oct 1861, probably from Athens
(where Schmidt had become director of the observatory 3 years earlier) with a
6.2-inch Ploessl refractor. He made a micrometric measurement of it, and
provided a generic description, "A faint nebula." Auwers lists this as the
first object in his appendix of nebulae discovered since the Herschels.
Schmidt's position is within 3 arcsec of the star, so it is almost certainly
the object he saw.
=====
NGC 33 is a double star. The comment for NGC 30 fits this perfectly, too.
The only difference is Marth's description: "eF, vS; or nebulous star."
=====
NGC 34 = NGC 17, which see.
=====
NGC 37. See NGC 28.
=====
NGC 44 is a double star found by John Herschel. He describes it as "eF, vS;
not to be seen but in the clearest night." There is a very faint galaxy 8.4
arcmin south of Herschel's position, but the double is within 15 arcsec and
fits his description.
=====
NGC 46 is a single star. Included as a nebula in the Markree Catalogue, it
was reobserved twice in its catalogued place by Auwers who notes it as "...
a completely sharp nebulous star 11th magnitude (9 arcmin north and 1 min 29
sec preceding a star 7.8 mag)." The 7.8 mag star is SAO 109091 which is
exactly where Auwers says it is with respect to NGC 46. This positively
identifies N46 as the star, as does the Markree position which is within 4
arcsec of the GSC position.
=====
NGC 47 = NGC 58, which see.
=====
NGC 50. See NGC 58.
=====
NGC 54. See NGC 58.
=====
NGC 55. See IC 1537.
=====
NGC 56 is lost. It may have been the edge of the gegenschein, or another part
of the zodiacal dust, but I think that is unlikely. Dave Riddle has also
suggested that it could be part of the infrared "cirrus" in the area (the IRAS
100-micron image shows it well), mirrored by a recent (2006) observation of
carbon monoxide there. However, I don't think that this will work, either.
Whatever happened, there is certainly more to the story than I typed in a few
years ago. Here is what I previously wrote:
NGC 56 does not exist. John Herschel recorded it only once very early in
his observing career (Sweep 14 in 1825), saying, "About this place a
considerable space seems affected with nebulosity." There is a possibility
that he saw a reflection of the bright star 2 degrees north, but there is no
other reasonable explanation for the observation. The other objects that he
recorded in Sweep 14 (including M 15) are all in the same area of the sky,
so there is no gross error in the position.
JH's observation took place on 13 October 1825. Assuming that what he saw was
indeed the gegenschein, and that its peak brightness is exactly opposite the
sun, it would have an ecliptic longitude of 19d 58min on that date,
corresponding to RA 01 13.7 and Dec +07 49 (B1950.0). The nominal position of
NGC 56 puts that 15d 38min away. Since the gegenschein is typically seen to
be about 10d across, it probably was not affecting Herschel's field that
night. If it was, it is also reasonable to ask why JH did not put the center
of his nebulosity nearer the gegenschein's peak.
Similar objections can be made to the IR cirrus hypothesis. The nearest
bright knot in the cirrus is about 5 degrees south and a bit east of NGC 56's
nominal position, but there is nothing at all to be seen on the visual
wavelength sky surveys anywhere in the area. Since JH was observing visually,
we want to find a visual source corresponding to his observation. It's not
there, unfortunately, so we are pretty well stuck for an explanation.
Dave also points out that there are three of WH's "extensive diffused
Nebulosity's" in the area. Is NGC 56 perhaps one of them? JH called it a
"nova" and did not mention, with respect to it, any of his father's large,
faint nebulae in notes to either his 1833 catalogue, nor in the GC of 31 years
later. The nearest of WH's nebulae to NGC 56 is 2.5 degrees away (WH's number
2 in his 1811 list published in Phil. Trans. 74, page 269). Since WH has his
estimated size at 3.3 degrees, the edge of the nebulosity is still 1.4 degrees
from the center of NGC 56. So, I would have to agree with JH that his
apparent nebulosity is not the same as that recorded by his father.
Are there more recent observations here? Dave points to several by Arthur
Searle reported in the Harvard Annals in 1900 which seems to trace the IRAS
nebulosity. But this is still well off NGC 56, so it seems unlikely to be the
same object. Similarly, IC 14 (Bigourdan 104) is sometimes suggested as a
part of JH's object. But it is clearly a faint double star; see the IC file
for that story. Bigourdan, by the way, did not find NGC 56, noting only a
13.3 mag star near the nominal place.
In the end, my conclusion is the same as it was earlier -- NGC 56 is lost.
But the story is a lot more interesting now. Thanks, Dave!
(Also see NGC 7088, "Baxendell's Unphotographable Nebula", for a similar large
non-existent object.)
=====
NGC 58 = NGC 47. The brightest (N50) of the three nebulae (N47 and N54 are
the others) in this group was found in 1866 by Brother Ferrari at the Vatican
Observatory. It is one of only two in his short list, published in a note in
AN 1571 by Father Secchi (the Observatory's director), which has a fairly
accurate position. See NGC 7667 for more information about Secchi's note.
Sometime later, Tempel went over the field and found Ferrari's nebula as well
as a second nearby, N47. It seems likely that Tempel actually saw all three
galaxies here, though Dreyer credits Tempel with observing only two of them
(Wolfgang suggests that this might be one of Dreyer's rare errors). There is,
by the way, no record of any of these in any of Tempel's ten published notes.
So, he must have "announced" them in a letter to Dreyer. His position for
N47 is good.
Finally, on 21 October 1886, Lewis Swift saw all three nebulae. Since
Secchi's position for the brightest is not exactly on the galaxy, and having
no way to know of Tempel's observation, Swift included the three as new in his
fifth list. Curiously, Dreyer credits only Secchi for N50, though he lists
Swift as having observed the other two.
Though Swift calls N58 the "3rd of 3," it is actually west of the other two.
Swift's RA is in error by about 1 minute of time. This was noticed first by
Herbert Howe who could not find N58, and suggested that Tempel's object, N47,
is also the object seen by Swift. This, of course, makes it the "1st of 3,"
and suggests that Swift added the comments based on the positions in his list,
rather than on his actual observations.
=====
NGC 59 is one of the nebulae found by Ormond Stone with the 26-inch refractor
at the Leander McCormick Observatory in the mid-1880s. While most of the
positions for these first nebulae found at LM are pretty poor, we have in this
case (and about 190 others) a sketch to confirm the object in its surrounding
star field. In addition, Stone has written the discovery date on the sketch
cover sheet: November 10.4 1885.
Bob Erdmann was curious about that "10.4": Was that really the date -- and
time -- of the discovery? That set me to pondering, and this is what I
eventually sent to Bob.
The ".4" is indeed 4/10 of a day, or 9h 36m. I do not know if this is UT or
local time, though. But I suspose we could work it out: I don't think they
observed the thing at 9:36 in the morning, and since L-M is 6hr behind
Greenwich, that would make local time at 10.4 UT something like 10:15 or
3:15+-AM local, which sort of makes sense for an observation of an object at
RA = 0h 10m, -22d 03m (1890) in November. We can check that: Let's see ...
on November 10, N59 crosses the meridian at about 3+ hours before midnight,
so its hour angle at 3:15AM local time is about 3h25m which puts it pretty
deep into the southwestern sky. Assuming they did not have a right-angle
prism on the 26-inch, that would make for pretty comfortable observing,
which at that time on a cool, fall night would be important.
The LM observers wrote the RA and Dec on the cover sheets, too, providing an
additional check on the identities. Finally, they gave us the page number and
"book" number, probably an observing or log book, along with the power at
which they observed the object. In this case, the power is 250, as it is for
most of the observations. Some of the smaller and fainter nebulae, though,
were observed at magnifications of up to 500.
=====
NGC 61 is the brighter, southern component of a double galaxy found by WH.
His description, "irregular figure," suggests that he might have glimpsed
the fainter component to the north, too. The MCG position (copied into RNGC)
is incorrect, SEGC (in RC3) is correct.
=====
NGC 67 is the westernmost and faintest of at least seven nebulae found by LdR
in what we now call the NGC 68 group. His fine sketch, published in his 1861
monograph, clearly shows that the object that most of us have been calling
NGC 67A is, in fact, the object LdR sketched as one of the nebulae. The
object we've been calling NGC 67 is shown on LdR's sketch as a star. So, I've
reassigned NGC 67 to the correct galaxy to properly reflect the history.
The other NGC objects in the group (N68, 69, 70, 71, 72, and 74) are brighter
and have been correctly identified in the major catalogues.
=====
NGC 68 is the brightest galaxy in a compact group. WH listed one of his fifth
class ("large") nebulae here, so I think it likely that he saw the merged
light of at least NGC 68, 70, and 71, the three brightest in the group.
Several of the stars in the vicinity probably also added to the "object" that
WH catalogued.
LdR picked out seven of the nebulae here, and suspected at least two others.
His sketch shows the seven, along with several stars, two of which turn out to
be galaxies. See NGC 67, IC 1538, and IC 1539 for more on this group.
=====
NGC 69. See NGC 67.
=====
NGC 70 = IC 1539, which see. Also see NGC 67 and 68.
=====
NGC 71. See NGC 67 and NGC 68.
=====
NGC 72. See NGC 67.
=====
NGC 74. See NGC 67.
=====
NGC 78. This is usually taken as the northeastern of a close pair of
galaxies, because that galaxy is brighter and has a higher surface brightness.
However, I'd like to be sure that this is the case as the differences between
the two galaxies are not large. I am hoping that Pechule's discovery paper
will tell us which of the two nebulae he found, but am not hopeful -- nebulae
were definitely not Pechule's main interest (see e.g. NGC 4239).
In any event, we have not yet tracked down Pechule's paper (and Dreyer does
not give us any more reference than Pechule's name), but it must have appeared
between 1864 and 1879, the publication dates for the GC and the GC Supplement.
The object is listed only in the Supplement. (Wolfgang is looking for the
paper, too; November 2005).
-----
Note added in February 2017: Wolfgang, in his 2010 book "Observing and
Cataloguing Nebulae and Star Clusters", states that Pechule did not in fact
publish this discovery. So, it must have been brought to Dreyer's attention
in a letter or other private communication.
=====
NGC 81. Even though Bigourdan mistook the star northwest of the galaxy as
NGC 81, Copeland's offsets from NGC 83 are very good and point unambiguously
at the galaxy as the correct object.
=====
NGC 82. Bigourdan's offsets just as unambiguously point to a star in this
case as in his mistaken observation of a star for NGC 81.
=====
NGC 83. See NGC 81.
=====
NGC 84. As with Bigourdan's measurements of NGC 81 and 82, this, too, is a
star, nailed exactly by those measurements.
=====
NGC 85. I admit to caving in to the inevitable on this one. There is no
problem with the NGC identification -- Copeland's offsets from NGC 83 are
accurate, and just as accurately pin down the galaxy he measured. Similarly,
Javelle's offsets from SAO 073902 are good and pin down IC 1546.
The "A" and "B" suffixes for NGC 85 come from MCG, and confuse the simplicity
of the history. I was tempted to ignore the suffixes altogether, but they
have already been copied into the literature. So, I have to note that "N85B"
is the same as IC 1546.
=====
NGC 90, 91, and NGC 93. Dreyer has confused the observations of these
objects. Lord Rosse's observations make it clear that he and his assistants
saw only two nebulous objects here, so one of the "Ld R"'s has to be
striken from the "Other Observers" column of the NGC. The offsets make it
clear that the Irish observers saw what we now call NGC 90 and NGC 93.
What do the observations of Schultz and d'Arrest have to say? Schultz's
positions for all three objects -- not just one as the NGC credits --
precessed from the published equinox of 1865.0, agree to within two or three
arcsec in all three cases with modern data from GSC. These pin down the
three objects and show that NGC 91 is a star (Bigourdan also called the same
star NGC 91 in his Observations). D'Arrest's positions are not quite as good,
but fall within 20 arcsec of the galaxies. His descriptions of the locations
and magnitudes of the nearby stars are also good, and confirm the
identifications.
So, NGC 90 should be credited to Lord Rosse, Schultz, and d'Arrest (rather
than just Lord Rosse and Schultz), NGC 91 to Schultz alone (Lord Rosse and
d'Arrest never commented on this star), and NGC 93 again to all three
observers. To the description for NGC 90 should be added "* 13 sp."
There are several other identification problems in the NGC 80/83 Group, too.
See NGC 81, 82, and 84, as well as IC 1547.
=====
NGC 91. See NGC 90.
=====
NGC 93. See NGC 90.
=====
NGC 110. Is this a true cluster, or just a part of the northern Milky Way
that is randomly richer? JH found the grouping in late October 1831, and
described it as "A very loose, pretty rich cluster; stars 9th to 12th
magnitude; 9th magnitude star in the middle taken." Assuming that JH's
position is correctly reduced and printed, the 9th magnitude star is GSC
4303-1643 at 00 27 25.4, +71 23 27 (J2000.0; I've adopted this position --
rounded off -- as the position of the cluster).
Looking at the object on the POSS1 does not show much beyond a group of 50-60
stars scattered over an area about 20 x 15 arcmin across. Had this not been
included in the Alter-Ruprecht catalogue, I suspect that it would have been
one of the RNGC's "nonexistent" clusters.
There is the possibility of a mistake in JH's single position, but I don't see
any other grouping in the area that would fit his description as well. I
think this is a candidate for visual observation.
-----
Note added in October 2003. Bob Erdmann and I examined the cluster a couple
of weeks ago under good skies in Prescott, AZ with 8-inch and 16-inch
telescopes. JH's description from the eyepiece is more appropriate than mine
from the POSS. The "cluster" is just a bit more than a random scattering of
15-20 stars from the 9th to the 12th magnitudes in an area about 20 arcmin
across. It doesn't stand out very well from the field, but we can still see
why JH recorded it.
-----
Looking at the DSS2 red image in December 2016 simply confirms what I say
above about this "cluster". However, I put the center of the cluster about
three arcminutes northwest of the GSC star.
The recent cluster compilations based on proper motions and photometry (e.g.
Dias et al 2014 and online at http://www.wilton.unifei.edu.br/ocdb/; Karchenko
et al 2013, available through SIMBAD) make the cluster a bit smaller (12 to 14
arcminutes) and put the center close to the GSC star that JH noted. So, as
before, I've simply adopted that position for the object.
=====
NGC 111. I cannot see anything within 5 degrees of Leavenworth's position
that agrees with his description of a "vF, vS, R, lbM; * 8.5 p 36 sec, n 2
arcmin. [alpha] doubtful." There is a very faint, peculiar pair of galaxies
(MCG -01-02-013) at the approximate offsets he gives from the nearby star --
but the star is 10th or 11th magnitude, and his description of the galaxy does
not match the relatively low surface brightness twisted streamers that
contribute most of the light of the pair. There is no sketch included in
Stone's papers at the University of Virginia.
The galaxy may not be irretrieveably lost, however. Since the declinations
in the first two Leander McCormick lists are generally (though not always!)
reliable to within a couple of arcminutes, it may be possible to scan around
the sky at Leavenworth's declination to find the object (see e.g. NGC 331). I
haven't tried yet, however.
-----
In July 2016, John Ponting sent around an email suggesting that this object
may be identical to NGC 758 (coincidentally also found by Leavenworth). The
descriptions are very similar ("vF, vS, R?; [alpha] doubtful"), and the star
is there. The problem, of course, is that the (doubtful!) RA is 1.5 hours
different, and the declination is 20 arcminutes off, too. John suggests that
Leavenworth confused his hour angle reading at the telescope making it
positive instead of negative. This could have added 1.5 hours to the RA.
NGC 758 has a star of the right magnitude at the right distance to the
west-northwest which gives further confidence in the identity. This all
strikes me as reasonable, so I have listed the identity as a possibility.
=====
NGC 116 is the last of fourteen new nebulae found by Brother Ferrari at the
College Romain during the winter of 1865-1866. They were announced by Father
Secchi, and Dreyer incorrectly credits him with their discovery. See NGC 7667
for more information about Father Secchi, Brother Ferrari, and their nebulae.
This particular nebula is unusual in the list in having a candidate galaxy
nearby (about 15 arcmin north of the nominal position), MCG -01-02-017.
There is another galaxy about eight arcmin southeast (MCG -01-02-018), closer
to the nominal position, but fainter. Finally, Courtney Seligman adds an even
fainter object, PGC 169989, which is about six arcminutes west of the nominal
position.
Most of us take the brighter, northwestern galaxy, but given the poor
discovery position, that is obviously unsure.
=====
NGC 120 is correctly described as being about 10 arcmin north of the
comparison star in Tempel's original paper. However, as noted first by
Bigourdan, the NGC position is about 5 arcmin off. This is apparently one of
the positions that Tempel sent to Dreyer as a private communication since only
the description is published. See NGC 122 and NGC 123 for a bit more.
=====
NGC 122 (and NGC 123, which see) is probably a star. Tempel published only
the sparce descriptions; the NGC positions are apparently among those that he
sent directly to Dreyer. There is certainly nothing at these positions except
a faint star in the case of NGC 122 (which Bigourdan measured). Ironically, I
think that this star may be the northeast of Tempel's "nebulae," so that it
would be NGC 123 and not NGC 122. NGC 122 may be the equally faint star about
an arcminute southwest of Bigourdan's star. See NGC 123 for more.
=====
NGC 123 is probably one of two 15th magnitude stars, both in GSC, near
Tempel's positions (see NGC 122 for more on this) in roughly the correct
relative positions. Since there are no nebulae anywhere in the area, I've
tentatively identified these two stars with the objects he described. A
brighter galaxy, NGC 120 (which see) is further on to the northwest, again in
the correct relative position which Tempel described in his paper.
Bigourdan measured this star, but gave it the number NGC 122; there is nothing
at all at his one measured place for NGC 123.
Finally, in his early lists, Wolfgang made the star I've chosen as NGC 123,
"NGC 122", and put "NGC 123" on another star. However, the relative positions
are not accordant with those given in the NGC, so I have given those possible
identifications lower weight.
=====
NGC 128 is the prototype of the edgewise early-type galaxy with a "box/peanut"
central bulge. See e.g. the entry in the "notngc" files under "NGC 7556
companion" for another example.
=====
NGC 135 = IC 26. There is no doubt about the identity of IC 26 -- Javelle's
position agrees to within 2 arcsec of that measured on the DSS. The problem
comes from Leavenworth's position for NGC 135. Like many of the positions in
the two lists of new nebulae from Leander McCormick Observatory, that one is
over a minute of time off in RA, though much closer in declination (less than
2 arcmin off).
Herbert Howe went after the object around the turn of the century (19th to
20th) and said simply, "The position is 00h 26m 43s, -13d 53.3m [1900.0]."
This agrees exactly with the position for IC 26. Leavenworth has left us a
sketch that verifies Howe's object, so the identity is secure.
It's interesting to note, too, that the cover sheet for the sketch has the RA
given to a tenth of a minute (00h 24.8m), while the RA in the published paper
is rounded off to 00h 25m. I won't even speculate on why this was done.
=====
NGC 151 = NGC 153, which see.
=====
NGC 153 = NGC 151. Swift found four nebulae on the night of 9 August 1886
(N163, N217, and N7774 as well as N153) -- all have RA's in his list that are
10 - 15 seconds of time too large, though his declinations are pretty good.
As it happens, all but N7774 had been previously seen. Dreyer caught the
identities for two of the nebulae (N163 and N217), but not for N153. So, the
galaxy now has two NGC numbers.
N153 is sometimes taken to be the star just northeast of the galaxy. But this
can't be because Swift mentions that star in his description of the galaxy.
There is also a faint galaxy just southwest of the star; this is presumeably a
background object.
=====
NGC 156 is probably the northern of the pair of stars, northwest of NGC 157,
that Wolfgang and I have pointed to in the past. Tempel has mistaken several
other single stars near galaxies as nebulous (see e.g. NGC 122/123, NGC 4315,
NGC 4322, NGC 4768/9), and this is probably another. We can't tell for sure,
though, as he has not measured this micrometrically, and his description is
scanty: "Very small". The NGC tells us all that Tempel did in his brief
note.
There is, of course, the possibility that his object refers to both stars, so
I've included that in the table, too.
=====
NGC 157. See NGC 7667 where this galaxy -- NGC 157 -- figures in the Father
Secchi mysteries.
=====
NGC 158. Though this is 4 arcmin from the NGC position, this single star (not
a close double; see the next paragraph) is probably Tempel's object. It is
northeast of NGC 157, and is similar to many other of Tempel's stars that he
mistook as nebulous. I'm a bit more confident of this one than I am of NGC
156, which see.
-----
Having looked at this again (August 2015), I no longer think that this is a
double star. The SDSS image -- the highest resolution image I've found online
-- is resolutely single when compared to other single stars nearby. The other
images I've looked at today are also single stars, so I've changed the
position table to reflect this. Sorry to have misled you all this time.
=====
NGC 160 is not NGC 162, which see.
=====
NGC 161. See IC 1557.
=====
NGC 162 is a star about 75 arcsec northeast of NGC 160. It was initially
found and measured by Schultz at Uppsala (he calls it "G.C. 80" in his tables
and notes), though Lord Rosse also noted it at least twice. In addition, the
star was thought to be nebulous on Heidelberg and Lick plates, though the Mt.
Wilson astronomers -- not finding a nebula at the place -- hypothesized that
N162 = N160. The small galaxy 2.7 arcminutes southeast of N160 has also been
mistaken for NGC 162, once by yrs trly. Live and learn.
Also see Dreyer's NGC note for N160. He had this all figured out in 1888.
=====
NGC 163. This is not H III 954; see NGC 165 for the short story. Also see
NGC 153 = NGC 151 where this figures in the identification of NGC 151.
=====
NGC 164. See IC 1560.
=====
NGC 165. Steve Gottlieb, re-reducing WH's observation, has found that H III
954 is probably not NGC 163 as Dreyer supposed, but could well be this galaxy,
the following of a pair. WH's reduced position falls much closer to this than
to NGC 163, though a little doubt remains as WH's description is sparse: "eF,
S, excessively F". WH has another galaxy (NGC 153) in the same sweep, with
offsets from the same star (8 Ceti). WH's position for that galaxy is good,
so we can presume that -- barring a blunder -- his position for III 954 is
also good.
NGC 163 was found by d'A and measured by him on two nights in Sept 1865; his
position is accurate. He assumed that he saw the same galaxy as WH, and notes
the 32 second difference in the RAs.
Both galaxies were seen by Tempel. In his paper (in AN 102, 225, 1882 = AN
2439) he says, "Following III 954 -- observed by [WH] and d'A -- by 30
[seconds of time] is a larger though fainter nebula with a star in the middle;
a small star follows the nebula close to the north." Tempel clearly thought
that WH and d'A had seen the same galaxy, and that his second object was a
"nova". Dreyer adopted this interpretation for the NGC.
Finally, Swift has an observation of one nebula here on 9 August 1886. His
position, 00 36 14, -10 07.3 (precessed to J2000), is a almost exactly midway
between the two galaxies. Note, however, that the RA's of the galaxies found
on this night are 10-15 seconds of time too large, so this is almost certainly
an observation of NGC 163, as assumed by Dreyer. Swift's description "eF, vS,
R; v diff; only 1 * v near" could apply to either object, but fits NGC 163
well enough.
So, to summarize, WH and Tempel saw NGC 165; while d'A, Tempel, and Swift saw
NGC 163.
=====
NGC 171 = NGC 175. Dreyer (1912, WH's collected papers) tells us that CH made
a 1 degree error while reducing the position of III 223. There is certainly
nothing in the place given in NGC, though the identity with III 223 carries
two question marks. Auwers has the correct declination in his published
reduction of WH's observations.
The spare number comes from GC. Unfortunately, JH has no note there telling
us why he put the number in. However, in CGH, he notes the 1 degree
difference in the polar distances between III 223 and h2334 (N175) while again
putting a question mark on the number from his father's catalogue. Enough
doubt apparently remained in his mind about the identity that he put two
entries into GC, both of which Dreyer copied into the NGC. Dreyer checked
back into WH's manuscripts while working on the Collected Papers, and found
CH's error.
=====
NGC 175 = NGC 171, which see.
=====
NGC 178 = IC 39. The IC identity is not in doubt. Javelle's micrometric
measurement reduces to within a few arcsec of the modern position.
The NGC number, though, comes from one of Ormond Stone's Leander McCormick
discoveries with its typically bad RA. Stone's declination is fortunately
close, and his description "F, S, mE 0 deg, bM, faint wing sp" fits the galaxy
perfectly. The "faint wing" is, in fact, one of the arms of this object. I
wonder if this is a superposition of two galaxies, or an interacting system.
Stone has left a sketch of his nebula -- my rather poor copy of it shows the
"wing" faintly. Unfortunately, the sketch shows only the galaxy; no nearby
stars are included, so the identity is not quite pinned down. At least the
galaxy itself is oriented along the north-south axis of the sketch with the
"wing" apparently stretching off towards the southwest.
Herbert Howe found the galaxy 1min 37sec following Stone's position, so the
corrected position made it into the IC2 Notes. Unfortunately, Dreyer did not
notice that the object is the same as IC 39, so the identity of the two
numbers was not published until one of the Helwan observers noticed it.
=====
NGC 203 = NGC 211, which see.
=====
NGC 206 is a star cloud in NGC 224 = M 31, the Andromeda Galaxy. There is
another similar star cloud at the opposite end of M 31; see its story in the
"notngc" files where I call it the "Barnard And SC".
=====
NGC 211 = NGC 203. Stephan misidentified his comparison star as BD +2 92; his
star is actually GSC 0014-1250, not in BD. Within his mean errors, Stephan's
offsets, applied to the correct star, point exactly to NGC 203. This was
later picked up by Copeland with LdR's 72-inch, and was correctly positioned
by him.
A star that I had earlier pegged as the possible object that Stephan saw is
about 0.5 arcmin south-southeast of Stephan's incorrect position used in NGC.
Though I've not reduced Bigourdan's two measurements of "NGC 211," I suspect
they refer to this same star.
=====
NGC 213. See IC 1572.
=====
NGC 217. See NGC 153.
=====
NGC 218. Steve Gottlieb found that Esmiol has listed this discovery of
Stephan's with a different RA offset. Once the correction is made, Stephan's
offsets point exactly to UGC 480, the brighter of an interacting pair (VV 527).
UGC 440, the galaxy that we all previously took to be NGC 218, is not only not
at Stephan's offsets (even the wrong ones), but is nearly two magnitudes
fainter than UGC 480. Steve has finally found the correct galaxy.
Stephan found nine galaxies that Esmiol listed as "Anonyme" (without NGC
number); six have turned out to be NGC objects, while three did not make it
into the catalogue. See the discussions under UGC 3840 in the "notngc" files
for more on Stephan's observations of these galaxies.
=====
NGC 219. See IC 44.
=====
NGC 220. JH has this in three sweeps with accordant positions. That position
is also close to the cluster we usually put this number on, so the identity is
not in question. He may also have picked up the cluster in a fourth sweep as
well; see NGC 222 for that speculation.
What interests me is the relationship of this cluster to two others in the
area which have traditionally carried the numbers NGC 222 and NGC 231, both of
which see. JH refers to these in his description in Sweep 625 on 20+-
September 1835 (see my comment at the end of this note about the uncertain
date): "The first of an irregular string of nebulae and stars which descends
at an angle of about 45 degrees from the centre to the edge of the field (i.e.
in a northeastern direction)."
The string of stars is certainly there (see my notes about NGC 222 and NGC
231), though there is no nebulosity involved, at least in the DSSR2 image of
the area -- JH was probably seeing the unresolved background light of the SMC.
Archinal and Hynes also have a discussion of this string of clusters, noting
that it is probably Dunlop's number 2 in his 1826 list.
Finally, I see that in his table of Sweeps, JH has "no such sweep" noted in
place of a date for Sweep 625. Sweep 624 was made on 19 September 1835, and
Sweep 626 on 21 September. The date I've adopted is an interpolation, of
course, but it may have been on either of the adjoining dates. Another
possibility is that the Sweep is indeed non-existent, and those objects marked
with its number may be from other sweeps.
-----
In May 2016, I checked JH's sweeps in the Herschel Archive and find his
comment "Sweep 625 No[.] omitted by mistake -- no such Sweep exists." On the
right-hand page, he also writes, "625 = 626". He notes the date as 21
September 1835. So much for the mysterious "no such sweep"!
=====
NGC 222, though usually taken as a smaller, fainter cluster northeast of
NGC 220 (which see), may in fact be a fourth observation of NGC 220 itself.
The other three observations are from Sweeps 482, 625=626 (see my comment
about this sweep in the note for NGC 220), and 745. These have reasonably
accordant positions and descriptions.
NGC 222, on the other hand, was picked up in a single sweep (441 on 11 March
1834), and -- if it is NGC 220 -- has a discordant position (all these
positions are given in the big table). JH notes that this sweep was "below
the pole" in the descriptions of several other objects including NGC 242, 248,
294, 346, and 371. Some of these are also noted as having uncertain positions
in the sweep which adds to my own uncertainty about the observation of NGC
222.
JH made its position 3-4 seconds east and 4 arcmin south of NGC 220. His
description reads simply "vF, R, outlying". I suspect the "outlying" refers
to its position in the SMC.
The faint cluster, ESO 029-SC004, usually carrying the number "NGC 222" is 14
seconds of time east and 1.1 arcminutes north of NGC 220, not a good match at
all for JH's object. That position, and the fact that JH did not record NGC
220 in Sweep 442, leads to my skepticism in accepting the faint cluster as a
genuine discovery by JH. So, I've put my usual question marks on the numbers
in question.
See Archinal and Hynes for a similar discussion, though they eventually accept
the modern identification.
Jenni Kay, in her "A Visual Atlas of the Magellanic Clouds" also accepts the
modern identification of NGC 222, but without question. Using an 8-inch
Schmit-Cassegrain telescope at 110X, she found it "small, round, faint" and
"noticeably fainter [than] its neighbour NGC 220."
-----
In May 2016, I re-reduced JH's observation from the sweep, using the previous
object in the sweep, HD 3719, as a reference star. There is no mistake in
JH's own reduction, but I wondered if a wire error might be possible. He has
wire "2" recorded in the sweep. If he, in fact, used wire "1", then the RA of
NGC 222 would be 00 38 31 (J2000) -- there is nothing in that RA at his
recorded declination (-73 27.9; J2000). If he had actually recorded the
object leaving the field, the RA would be 00 44 01 (also J2000); this position
lands about 2.4 arcminutes southeast of NGC 242 = NGC 241 (which see for
problems of its own). However, NGC 242 is the next object in Sweep 441, so it
is not NGC 222.
JH has a curious note at the end of the sweep: "[Vision?] bad objects faint
and much light cut off by tree tops (to be cut away)". There is another line
at the bottom of the page, but it is mostly illegible in the high-contrast
Herschel Archive reproduction. The "tree tops" comment is fascinating, though
JH notes in CGH under his entry for NGC 242 in this sweep, "(in a sweep below
the pole and ill-seen) the RA is probably also in error."
All of this reinforces the idea that NGC 222 is actually a fourth observation
of NGC 220. So, I've replaced the question mark on this possibility with a
colon, raising the identity to a probability, if not a certainty.
=====
NGC 223 = IC 44, which see.
=====
NGC 224 = M 31, the Andromeda Galaxy. This may well be the most famous galaxy
in the northern sky. A vital stepping stone in the extragalactic distance
scale, it is the brightest galaxy in the Local Group -- our own Milky Way is
the second brightest.
Curiously, in spite of its proximity, M 31 contains only one other NGC object,
the star cloud NGC 206. There is another star cloud at the other end of the
galaxy that could have been included in the NGC, but wasn't. See that story
in the "notngc" files where I label the "missing" object the "Barnard And SC."
=====
NGC 225. This cluster has a loose concentration in its southeast side that is
usually taken as the center of the cluster. I've kept the position (from
Brian Skiff) that clearly refers to this concentration, but looking at the
field, I put the center a few arcminutes to the northeast. This is a little
closer to the positions that WH and JH have left us. I also note that a star
on the northwestern side has a patch of nebulosity associated with it.
=====
NGC 231. JH describes this as "An irregular train of stars and nebulosity in
the Nubecula Minor. (Evidently that referred to in Sweep 625 [NGC 220, which
see].)" Given this, I think it is very doubtful that JH was seeing just the
small cluster which we have taken as his object ever since.
So, bucking tradition, I have used this number to include all of the clusters
in the "irregular train", NGC 220, the traditional NGC 222 (but see that for
some uncertainty of its own), as well as the small one which has carried the
NGC number for many years. I call that little cluster "NGC 231 core" to
distinguish it from the overall "irregular train".
By the way, I make the entire size of the "train" roughly 6.5 x 2.5 arcmin.
It may extend further northwest and southeast, but this is its obvious size at
first glance.
=====
NGC 241 = NGC 242. Earlier, I had a long discussion of the pros and cons of
this. What that ignored was JH's own correction to the NPD of NGC 241 =
h 2342; on the "Errata" page of CGH, he corrects the minutes of NPD from "31"
to "21". This brings it right into line with the rest of the observations of
the clusters from different sweeps. Here are the relevant positions and
descriptions for NGC 242:
Sweep 441: "pL; vF; R; vgbM; (in a sweep below the pole and ill seen) the
RA is probably also in error." 00 37 13.7:, 164 21 50.
Sweep 625: "A binuclear nebula, or two, vS, R, running together."
00 37 07.2, 164 22 22.
Sweep 738: "A small irresolvable knot in the bright part of Nubec. Min."
00 37 09.9, 164 22 18.
Compare these with his description and corrected position for NGC 241:
Sweep 482: "A vF, R nebula or group. (We are now fairly in the Nubecula
Minor, and the field begins to be full of a faint perfectly
irresolvable nebulous light)." 00 37 05.1, 164 21 32
The only question that remains is why JH himself did not notice that the two
objects are identical. That would have given us just one GC and one NGC
number for the object rather than two.
-----
Finally, this object figures peripherally in the identity of NGC 222, which
see. There is also an interesting note there about the telescope being aimed
so low that some of the light of the objects in Sweep 441 was lost in tree
tops!
=====
NGC 242 = NGC 241, which see. Also see NGC 222.
=====
NGC 246. The central star (HIP 3678 = BD -12 134) is a triple. The white
dwarf itself (HIP 3678A) has two companions, one visible on the DSS2 red and
infrared images; it is lost in the lower resolution of the scan of the
southern IIIa-J plate, but must be visible on the plate itself. Adam and
Mugrauer, MNRAS 444, 3459, 2014 have details about the triple star.
Sometimes called the "Skull Nebula", NGC 246 has several other stars
superposed on it. I've adopted the Hipparcos position for the white dwarf.
Curiously, the first Gaia data release includes the brighter of the two
companions, HIP 3678B, but not the white dwarf itself.
=====
NGC 247. While there is no mistaking this large galaxy -- one of the nearest
in our sky -- the position I've chosen still carries a whiff of doubt in my
mind. Is the object at that position the stellar nucleus, or is it a
superposed star? Concensus at the moment (December 2013), from various notes
and abstracts in NED, suggests it is indeed the nucleus. But I was unable to
dig out a spectrum of the object to be sure. Even if it is a star, though, it
is still a good proxy for the galaxy.
=====
NGC 248. See NGC 222.
=====
NGC 250. Swift's position is over 4 arcmin to the east of the galaxy. But
his description of the galaxy, "eF, vS, R; in center of 3 sts in form of a
right triangle" is exact and points us to the correct object.
=====
NGC 252, NGC 258, and NGC 260. Lord Rosse and/or his observers described this
field differently on different nights. On 22 Dec 1848, the three objects
appeared to be in a line; on 23 Oct 1856, they formed a triangle. He has two
sketches, one showing the line, the second the triangle. Since the second has
no field stars shown, it's difficult to determine the orientation. My guess,
however, is that the third "nebula" shown there is a faint star about 2 arcmin
south of the NGC position of N258.
On the sky, the three objects are in a line. This is the orientation that
Dreyer adopted, and the NGC positions are relatively accurate.
Incidentally, only NGC 258 is credited to "LdR" in the NGC; that credit also
needs to be added to NGC 260 (which see for a bit more).
=====
NGC 258. See NGC 252.
=====
NGC 260. Steve Gottlieb has pointed out that this object was first discovered
by Johnstone Stoney on 22 December 1848, one of two objects accompanying NGC
252 (which see). In his monograph, even d'A notes "One of Rosse's." So the
missing NGC credit must be a simple oversight by Dreyer.
=====
NGC 272 is an asterism of perhaps as many as eight or ten stars, but maybe
just five or six. d'A says of it,
Lucidissima stella (9-10 magn.) coacervationis cujusdam, ad normam lineae
curvae miro modo adornatae.
Google Translate makes a mess of this, but the basic idea is of a 9-10th
magnitude star accompanied by a curved line of fainter (my interpretation)
stars.
This is pretty much what we see on the sky today. However, Dreyer interpreted
d'A's description as "Cl, L, lC". I suppose that this is as close to the
original as Dreyer could manage without actually seeing the object. In any
case, d'A's stars are nothing more than an asterism a few arcminutes across;
his original position is pretty good. The positions I've listed depend on how
many stars are included in the object. While I'm inclined to go with just the
bright star and the half-circle of four stars (one double) to the southeast,
there are two other similarly bright stars to the north that Brian has picked
up for one of his positions. In the end -- not seeing much reason to omit the
northern stars -- I've taken that position of Brian's for the asterism.
=====
NGC 276 = IC 1591. There is no doubt about which galaxy the IC number belongs
to -- Stewart has it well-placed and perfectly described from a Harvard plate.
N276, however, is one of the Leander McCormick nebulae first found by Muller,
and published with a very poor position. Muller's description, however, is as
detailed and as accurate as Stewart's. Herbert Howe found the galaxy 1 minute
13 seconds following Muller's position with the bright star north-northeast
just as Muller had it.
Unfortunately, Dreyer did not catch the connection to IC 1591 when he wrote
the IC2 note, so the object now has two numbers.
=====
NGC 281 = IC 11, which see. Also see IC 1590.
=====
NGC 292 is the main body of the Small Magellanic Cloud. It's somewhat curious
that the Small Cloud has an entry in the NGC while the Large Cloud does not.
See the "notngc" file's entry on the LMC for more about this.
=====
NGC 294. The CGH, GC, and NGC RA's are -1 minute of time in error.
Curiously, JH notes the correct RA in his description in Sweep 441: "eF.
(This obs. gives 47 [instead of 46] for the [1830] minute of R.A. The earlier
minute is preferred.) In a sweep below the Pole."
Also see NGC 222 where the other uncertain positions from Sweep 441 have a
bearing on the identification of that object.
=====
NGC 295 is no longer lost, thanks to Yann Pothier. By way of background, here
is what I had to say about it earlier.
This object was found by Copeland with LdR's 72-inch reflector while he was
examining what he thought was NGC 296. His description of the field is
precise: "[NGC 296] F, R, *10m (yellow) Pos 29.6 deg, Dist 123.1 arcsec.
Nova [NGC 295], S, R, and with a * or another neb 10 arcsec n. Pos from
[296] 242.0 deg, Dist 314.6 arcsec or 21.6 seconds p, 147.6 arcsec s."
Unfortunately, this configuration of objects is nowhere to be found near NGC
296 (which see for more).
I've searched the POSS1 +30 deg 00h 52m field, but could find no galaxies
with neighboring stars as Copeland describes. Perhaps a search of the
adjacent fields would turn up something.
Yann succeeded where I failed. I suspect that I was looking for a relatively
bright galaxy; the actual object that Copeland thought was NGC 296 turns out
to be CGCG 501-058 = Markarian 352 with a V magnitude of 15.2 about a degree
away from the real NGC 296. When the CGCG galaxy is used, all of Copeland's
measurements and comments are easily verified, so the mystery of the identity
of NGC 295 is finally solved.
=====
NGC 296. WH's position is about 20 seconds too large and an arcmin too far
north. That alone would not have caused people to miss the identification
with the brightest galaxy in a group of five.
What caused the problem was NGC 295 (which see). Copeland misidentified the
field with N296, found a second object near it, and Dreyer put that into NGC
as number 295. Unfortunately, with WH's position being off, the nominal
position of N295 is very close to the actual position for N296. Hence, the
confusion.
The description in NGC is an "average" of WH's and Copeland's for the galaxy
he thought was N296. WH's original description "F, E, preceding a B star", is
closer, but the GC description (apparently taken from one of his father's
observing logs by JH) is even better: "F, E, a B* f, vnr."
Just about everyone has the wrong identification for this, but the correct one
is not in doubt. Malcolm found this one, too. Good catch!
=====
NGC 297 is an extremely faint companion to NGC 298. Both were found by Albert
Marth with Lassell's 48-inch reflector during one of their Malta stays. When
I first went over the field for SEGC, I found it hard to believe that such a
faint galaxy could be seen visually. However, more experience in looking at
some of the other objects Marth found has convinced me that he could indeed
have picked this one up, especially since the brighter galaxy would have
already caught his attention. In earlier versions of the position table, I
suggested that N297 might be the double star at 00 52 29.6, -07 37 50 (B1950;
HCo), but that is unlikely as the relative position of the two galaxies as
given by Marth is very good. The double is almost straight south of N298,
putting it about an arcmin off Marth's relative offset from N298.
=====
NGC 298. See NGC 297.
=====
NGC 301. See NGC 302.
=====
NGC 302 is a probably the star 1.8 arcmin east-northeast of NGC 301. The pair
was found by Frank Muller, and has a typically poor RA in the first list of
nebulae from Leander McCormick. The declinations, though, seem to be close.
Though there is no sketch, the objects can be tentatively identified by
Muller's comment "* 8 p 30 seconds" in the description of NGC 301. There are,
in fact, two stars of about 8th magnitude roughly 30 seconds preceding the
galaxy. The northern star is slightly closer than 30 seconds, the southern is
slightly further. It's possible that neither is the correct star, but this is
the only configuration in the area that fits Muller's note.
In any event, there is no object at his given offset from the galaxy (his note
reads "Neb? f ([No.] 18 [in the first list = N301]), P 75 deg, dist 1.0
[arcmin]." The actual distance is 1.8 arcmin, though the position angle is
about right.
Unfortunately, 20th century versions of my position lists pointed to the wrong
object as N302 (the faint star or compact galaxy 0.3 southeast of N301). The
first 21st century version finally got the right star -- assuming, of course,
that it is the object Muller saw.
=====
NGC 303. For some time, I had this as a double galaxy with the brighter of
the pair to the north. Looking at this again in August 2015, I now believe
that this is a single object with distorted arms to the south, a bright
central bulge, and a single knot to the northwest. The positions in the table
now reflect this thinking.
Unfortunately, there seem to be no high-resolution images of the galaxy
available. Courtney Seligman has given us color images from the DSS, and also
suggests that this is a single galaxy. But this is outside the SDSS footprint
and there are no HST images available, either.
But this does indeed look like a single peculiar galaxy, at least based on the
DSS2 images.
=====
NGC 305 is a small asterism of six or eight stars at JH's discovery position;
his description, "A small cluster of p closely scattered stars" confirms the
identification. RNGC incorrectly placed the NGC number on a nearby CGCG
galaxy. Unfortunately, PGC followed RNGC, so this number crept into RC3 as
well. Sigh.
The position depends a bit on exactly which stars are taken as members of the
asterism. Tom DeMary includes a few more than caught my eye at first, so his
position is about an arcminute different. But the identification as an
asterism is not in doubt.
-----
Coming across this again in March 2017, I dug out positions and proper motions
for the eight stars that constitute the main "body" of the asterism, hoping to
answer the following question: Could this be a real, albeit poor, cluster? A
definitive answer will have to await the arrival of the Gaia proper motions a
few years from now, but the tentative answer is "No, it is indeed no more than
a random collection of stars at different distances."
The problem is that the proper motions, with a few exceptions, are well within
the errors of being zero. For your information and edification, I've listed
in the big table a sampling of the proper motions that I found in the various
star catalogues. For most of the stars, the motions effectively scatter
around zero. I've calculated the means and standard deviations to satisfy my
own curiosity. These show that the stars I label "m" and "mw" are probably a
physical pair, but the others are scattered along the line of sight.
=====
NGC 307. See the "notngc" files as well as NGC 308 in this file.
=====
NGC 308 and NGC 310 are both stars. [All this is from a July 1989 letter to
Malcolm Thomson; it's a bit wordy, but I've saved it like this since it has a
few details in it about my pre-DSS working methods.] Since Lord Rosse
measured the positions of NGC 308 and 310 in relation to NGC 307, I decided to
do the same. Using a comparator with a millimeter scale and an "angle fan"
scale, I measured the distances and position angles of objects surrounding
NGC 307 on the Palomar Sky Survey print. Since the scale of the paper prints
is different in the x and y directions by about 0.9%, the measurements are
liable to be a bit off from what would be measured on a glass plate.
Estimating the center of NGC 307 was also a problem, and the resulting errors
probably swamped the print scale problem. Nevertheless, the measurements are
adequate to unambiguously identify the objects in question.
So, here is a table of the objects identified and measured by Lord Rosse and
myself. I've also included [Malcolm Thomson's] measurement of the galaxy
that the RNGC calls NGC 310.
Object Observer PA Dist Date Notes
(deg) (arcsec)
GC 5126 Ld. R. 147 60 31 Dec 1866 Measure obviously approximate
= N308 Ld. R. 149.7 52 23 Oct 1876 Mean of two measures
= star HC 150+- 52 14 Jul 1989 PA approx
GC 5128 Ld. R. 81 225 31 Dec 1866 "Another neb. susp. near."
= N310 Ld. R. 84.8 239 23 Oct 1876 One measure only
= star HC 84 231 14 Jul 1989
--- HC -- --- 25 Oct 1983 "Both novae are stars."
eF nova Ld. R. ssf 3-4 min 8 Nov 1866 Estimated position
Stars HC (same) (same) 14 Jul 1989 "Only stars here"
Star Ld. R. 199 225 31 Dec 1866
Ld. R. 201.6 240.1 23 Oct 1876 "* 11m. sp [GC] 172"
HC 201 235 14 Jul 1989 On [Thomson's] sketch
Star Ld. R. 0+- 3.25min 23 Oct 1876 "* 11.12m, 3.25min exactly
north of [GC] 172."
HC 357 170 14 Jul 1989 On [Thomson's] sketch
Gal B HC 91 303 14 Jul 1989 On [Thomson's] sketch
MT 90+- 4min Jun 1989?
Gal C HC 215 185 14 Jul 1989 On [Thomson's] sketch
Gal "D" HC 338 92 14 Jul 1989 On [Thomson's] sketch, unlabeled
That's all the observations there are, aside from the modern work on NGC 307
(photometry, spectroscopy, etc.). Dreyer's NGC positions (and the offsets
from NGC 307) are derived from Lord Rosse's measurements, so don't give us any
new data. As you can see, my measurements agree (within the errors, a few arc
seconds, and about 2 deg in PA) exactly with Lord Rosse's, and pinpoint the
two stars as the "nebulae" that he found. Adding to my conviction that this
must be correct is the fact that the galaxies C and D are approximately the
same brightness as B, yet Lord Rosse mentions neither, in spite of the fact
that he noticed the star further to the north of D and NGC 307.
I also suspect that [Thomson] is correct that the "...2st., 13.14 m. sf"
Lord Rosse's "...similar object, more stellar" seen during the 1876
observation are probably the two that [Thomson] mentioned, but that he (LdR)
again missed the real nebula (B). There is a faint possibility that Lord
Rosse actually saw the nucleus of B and just one of the sf stars, but this
would need confirmation. I think he also may have glimpsed the faint star
very close sff NGC 307 on 8 Nov 1866: "...on the p side is either a * close
or some other appearance different to the f. side." However, since there is
no star on the western side that I can see on the print, it is only the
"some other appearance to the f. side" that offers evidence of this, so I
wouldn't want to push this.
In sum, I have no choice but to stand by my original conclusion that both NGC
308 and 310 are stars mistaken for nebulae. The agreement in the distances
and position angles from NGC 307 allows no other conclusion.
-----
In March 2016, I received from Yann Pothier a list of "novae" in LdR's
monograph that included a galaxy near NGC 307. That galaxy is the one called
"eF nova" in the list above. Yann suggested that the object is actually the
faint galaxy south-southwest of NGC 307. Following up on this, I noticed what
at first I took to be a superposed star on the eastern side of the bright
galaxy -- above I quote the observation from 8 Nov 1866 (actually by R.S.
Ball, LdR's observer at the time) noting a star on the west side of the
galaxy. Since Ball was also responsible for the discovery of the "eF nova"
three or four arcminutes south-southeast, I'm going to suggest that he had his
directions reversed. So, if the superposed object -- actually a background
galaxy -- that he saw is on the eastern side of NGC 307, then the "eF nova" is
probably three or four arcminutes south-southwest. Indeed it is. See the
"notngc" files for a bit more.
=====
NGC 310. See NGC 308.
=====
NGC 311. See NGC 313.
=====
NGC 313 is a triple star (the third star is very close to the northern of the
brighter two) about an arcminute northwest of NGC 315. Lord Rosse and his
observers saw the group (NGC 311 and NGC 318 are the other two bona fide
galaxies in it) on six different nights, and saw the triple as nebulous on all
but one night when it was noted as a double star (the sketch was apparently
made on that night as it shows N313 as a double star). Micrometric offsets,
the final set by Dreyer, from N315 on three of the six nights point exactly to
the triple. In deriving the position from these measures, I've given Dreyer's
observations double weight; by the time of his measurements, LdR's micrometer
was a well-calibrated instrument, and Dreyer was skilled in its use.
The southern star of the triple is just bright enough that it was picked up in
GSC. The position I adopted when I first went over the field is midway
between this and the image of the northern two stars. By March 2017 when I
reduced LdR's measurments, SDSS DR13 and Gaia DR1 positions were available for
all three stars. Until Gaia releases proper motions for the stars, I have
adopted the SDSS positions.
=====
NGC 315. See NGC 313, NGC 316, and NGC 318.
=====
NGC 316 is a single star 45 arcsec east of NGC 315. The Parsonstown
observers have four micrometric measurements of it, all referred to N315, so
there is no confusion as to which object they were looking at. See NGC 313
for more on the observations of the field made with the 72-inch reflector.
=====
NGC 318. Even though Lord Rosse or R.J. Mitchell, his observer at the time,
saw this on just one of the six nights on which he observed the group around
NGC 315, it is nevertheless correctly placed in his diagram, and is correctly
described by him. The NGC position is pretty good.
=====
NGC 321. The mess with this number is partly my fault. While working on RC2,
I noticed that there is nothing at the (incorrect) RC1 position of "A0055."
However, MCG -01-03-041 is just one degree south and 0.1 minute east of the
RC1 position. I immediately jumped at this, and followed MCG in
misidentifying the galaxy as N321. Early versions of SEGC perpetuate the
error.
However, the real NGC 321 is actually MCG -01-03-043 (which MCG calls N325,
but that is MCG -01-03-45; are we confused yet?!). It was found by Marth in
August or September of 1864, and is the first -- and faintest -- of four. The
others are NGC 325 = MCG -01-03-045, N327 = MCG -01-03-047, and N329 = MCG
-01-03-048. Marth's positions are very good, and his brief descriptions are
appropriate. Even so, MCG managed to misidentify the first two of the four.
By the way: the galaxy called "A0055" in RC1 is MCG -01-03-041 (I got the
correct object, but put the wrong name on it). This object is the parent
galaxy of SN 1939D, discovered by Zwicky (see Harvard Announcement Card #518),
and included in his sample in ApJ 96, 28, 1942. He gives a relatively coarse
position (00h 54m, -05d 20m; labeled "1938.0" in the ApJ paper, but
"1939.0" in the HAC) which is nevertheless good enough to pinpoint MCG
-01-03-041 as the correct galaxy. He notes the type as "Sb" in ApJ; he
classified it on the 18-inch Schmidt film on which the supernova was found.
SEGC calls it "SB(r)c pec" from a glass copy of the 48-inch POSS1 plate, in
pretty good agreement. Zwicky also says in the HAC, "The spiral in which [the
supernova] appears belongs to a small group of nebulae including N321, N325,
N327, [and] N329 at the estimated distance of 7 million parsecs." Thus, the
galaxy cannot be N321, so we can take his position as correct and pointing at
MCG -01-03-041. (MCG -01-03-042 = Mark 966 is 4.0 arcmin on to the northeast,
and is compact and overexposed on the POSS1, showing little trace of spiral
structure; it would have been nearly stellar on the 18-inch films.)
=====
NGC 324. John Herschel's observation reads: "F; S; Stellar; the bad
definition of a south-easter prevents certainty, but I think it is not a
star." His position (precessed to 1950.0): 00 54 55 -40 43.2. There is
nothing here, but just 30 arcmin south at 00 54 56 -41 13.8 is a galaxy that
agrees with Herschel's description, and was taken by ESO and RC3 as N324.
I1609 (chosen by RNGC) at 00 57 28 -40 36.1 is also a possibility, but there
is no easy digit error in the position that could account for Herschel's
position. Therefore, I'm pretty sure that there is simply a 30 arcmin error
in Herschel's position.
=====
NGC 325 is MCG -01-03-045, not MCG -01-03-043. See NGC 321 for more.
=====
NGC 327. See NGC 321.
=====
NGC 329. See NGC 321.
=====
NGC 331 may be MCG -01-03-012 which is 11m 30s west of the very rough position
given by Leavenworth, who notes the RA as "doubtful." If we make a -10
minute correction to the RA, that places Leavenworth's nebula 1m 30s east of
the MCG object. This is within the errors of being at the +2 minute
systematic offset that many of the Leander McCormick nebulae show in their
RAs. The declinations are usually within an arcminute, and there is a star
(somewhat fainter than Leavenworth's rough estimate of 12th mag) three arcmin
northeast of the galaxy. Since there is no other reasonable candidate object
in the area, I've tentatively adopted the identification. There is
apparently no extant sketch.
Another suggested identification for N331 is MCG -01-03-039. But this has a
very bright star just 5 arcmin west-northwest. Leavenworth would almost
certainly have mentioned this, but does not. So, I think that is a less
likely candidate than MCG -01-03-012, even though it is closer to the nominal
position.
-----
Doing a search along a 1-degree wide declination belt at NGC 331's J2000 Dec
from 23 hours to 2 hours in RA turned up nothing at all that matched
Leavenworth's description better than MCG -01-03-012.
=====
NGC 333. See IC 1604.
=====
NGC 336 is not, as I supposed earlier, a double star. Thanks to the efforts
of Doug Wereb, Bob Bunge, and Brent Archinal, I have a notebook full of copies
of the discovery sketches of about a third of the nebulae found at Leander
McCormick. These are apparently all the sketches that still exist, and may be
all there ever were. In any event, NGC 336 is included among these sketches.
It is shown as a small, faint, circular nebula in a field including 3 stars.
Fairly close to the (very inaccurate) L-M position is ESO 541-IG002, a faint,
peculiar galaxy, perhaps a colliding pair, with the three stars shown in the
correct relative positions. The objects suggested as NGC 336 by ESO and RNGC
do not have stars nearby matching those in the sketch. Thus, they cannot be
NGC 336.
=====
NGC 339 is a globular (or rich open) cluster in the SMC. Its core is a bit
eccentric, being displaced about 10 arcsec to the northwest from the center of
the outer isophotes. Thus, the positions do not agree as well as might be
expected from the cluster's relatively small apparent size.
This is a feature shared by many clusters, nebulae, and galaxies. In general,
the positions I've adopted for the NGC and IC objects are meant to be
representative of the object as seen by the discoverer. Where the "feature"
becomes a problem, I've explicitely named the part of the object to which the
position applies. Thus, N339 has positions for its "core" as well as the
"entire cluster."
Finally, I have classified the SMC and LMC clusters purely on morphological
grounds. Thus, N339 is a "globular" cluster because of its richness,
compactness, and relative symmetry. An H-R diagram might tell a different
story. Folks interested in the astrophysics of these things will do well to
consult the literature to be sure about the classification of any given object.
=====
NGC 340. See NGC 347 and IC 71.
=====
NGC 342. See NGC 347 and IC 71.
=====
NGC 343 and NGC 344 are a pair of faint galaxies superimposed on the western
outskirts of a poor cluster of galaxies. Muller's position is about 4 minutes
of time too far west -- the same direction, though about twice as far, as many
other Leander McCormick objects are from their true positions -- but his
declination is good, and his descriptions are appropriate.
The galaxy and star taken as this pair in ESO are too far apart to match
Muller's relative positions, the star is too bright, and the galaxy has too
low a surface brightness and too faint a nucleus to warrant Muller's notation
"sbMN." RNGC also incorrectly picked this galaxy as NGC 344, and ESO may
have been following their lead.
=====
NGC 344. See NGC 343.
=====
NGC 345. See NGC 347 and IC 71.
=====
NGC 346. See NGC 222.
=====
NGC 347. This is one of a group of six nebulae found by Albert Marth (the
others are NGC 340, 342, 345, 349, and 350). There are other fainter nebulae
in the area, but Marth has picked out the six brightest. In particular, RNGC
got a somewhat larger, but fainter, galaxy about 4 arcmin to the south. This
is a spiral with low surface brightness arms, but with a bright nucleus. It
is not large enough to have made it into SEGC. I would guess that only the
nucleus would be visible at the eyepiece, and the proximity to the 7th
magnitude HD 6031 = BD -07 159 = SAO 129088 would make it even harder to spot.
The real NGC 347, which I picked up for SEGC, looks like a pair of interacting
ellipticals close to Marth's position (however, it could well be simply a
peculiar S0 with a dust lane, so I've retained just the single entry in SEGC).
The total magnitude is about the same as the RNGC object, but since this has a
much higher average surface brightness, it is more likely to be seen visually.
A couple of additional comments: Marth's positions are so good here that they
actually surprised me a bit. His positions have not impressed me in other
areas of the sky (e.g. NGC 1474, which see, and the other galaxies found that
same night -- five out of the ten are more than 5 arcmin off the true
positions). But in this area, the positions do seem to be pretty good, so I
followed them for the identifications.
Bigourdan's observation of NGC 347 may also be relevant. He observed it only
once (on 21 Nov 1889), but did not measure its position. His description
points clearly to the correct object, however: "I suspect an exceedingly
faint object which could be nebulous, and which is situated toward [PA =]
3 deg , d = 4 arcmin, with respect to BD -7 159." This is just where
Marth's position places NGC 347, another indication that this really is the
object which Marth saw.
=====
NGC 349. See NGC 347 and IC 71.
=====
NGC 350. See NGC 347 and IC 71.
=====
NGC 358. We've taken this as just the four stars near the d'A's position.
Dreyer's summary description "Cl, vl Ri" seems appropriate, given d'Arrest's
brief comment:
Compluscularum stellarum congeries -- levissimi momenti. Capta cum
inspicerem cumulum h. 83, qui ejusdem fere indolis.
For those, like me, who don't know Latin, the web offers several translators.
I tried a couple of them, and was finally able to come up with this:
A cluster of several stars -- not many members. Found when observing the
cluster h 83 [NGC 366], which is nearly of the same nature.
With all due respect to d'A, NGC 366 is a much more populous and impressive
cluster.
However, I suppose it is possible that d'A was including more stars in the
area in his own object. His position is about 1.2 arcmin north of the center
of gravity of the four stars. However, I don't want to make too much of this,
and will look to the visual observers for guidance beyond the asterism we've
chosen.
By the way, this probably is indeed an asterism. Given their lack of
significant proper motions, the two eastern stars are well in the background,
while the western stars have different proper motions from each other.
=====
NGC 366. See NGC 358.
=====
NGC 370. Is this NGC 372 (which see)? D'Arrest's description reads
(my translation), "Faint and diffuse, nucleus not condensed, * 13mag 15 arcsec
s." There is nothing at his position (accurately transcribed into the NGC),
but just 9 seconds of time east, and about 1 arcmin north is NGC 372 (which
see), a triple star. On a night of bad seeing, I suspect that N372 might
indeed match d'Arrest's description, though the 13th magnitude star -- which
is 10.1 arcsec from the other two in the triplet -- is east-northeast, not
south.
Thus, it could well be that d'A's object is really just the western two stars
of the triplet, rather than all three.
d'A's position is also well off; other nebulae in the group that he measured
the same night (7 October 1861) are close to his positions. So, I remain
skeptical, and there are question marks on this number in the table.
-----
Going over this again in August 2016, I see that d'A did not include this
night (nor 12 October 1861) among his numbered nights which start at "1" on
27 October 1861. There is no obvious reason for this that I can see from his
table. Perhaps he mentions it in the introduction to his observations, though
since I do not know Latin, I am clearly not the one to scan that.
-----
Stumbling over this once again in March 2017, I tried looking at offsets from
d'A's position for possible digit errors. I found nothing that matched his
description, particularly at one hour offsets (a few other of his positions
are one hour out). I did notice, however, that all the objects that d'A
observed on that October 1861 night are in the same area of the sky. In
particular, the declinations are all in the range of +29 to +32. Any future
searches probably don't need to go much further south or north.
I have also sorted out the stars, their positions, and their names. I had
made a bit of a mess of them earlier; my apologies!
=====
NGC 371. See NGC 222.
=====
NGC 372. This is a triple star west of the NGC 383 galaxy group. It was
found the night of 12 Dec 1876 by Lord Rosse or his observing assistant at
the time (Dreyer). The measured PA and distance from a star near the middle
of the galaxy group unambiguously identifies the object, as does the note in
its description about another 12th magnitude star at PA 166.5 deg with a
distance of 74.0 arcsec. The description itself is telling: "The last nova
looks at first sight like a hazy *, the higher power seems to resolve it, at
all events sev. luminous points were seen."
The triple, or perhaps the southwestern two stars, may also be one of
d'Arrest's "novae" (NGC 370, which see). I don't think this is the case, but
it is a possibility. See NGC 370 for the story.
=====
NGC 377 is positively identified as MCG -04-03-053 by Leavenworth's sketch and
description. His position is well off the mark, of course, so both ESO and
SGC missed the identification.
=====
NGC 383. See NGC 372.
=====
NGC 390 is a star. Bigourdan's offsets point exactly to a star at 01 05 08.6
+32 09 58 (B1950.0, reduced using the GSC coordinates for Bigourdan's
comparison star), and his description "vF, stellar" is that which he gives to
almost all of the stars which he mistook for nebulae. Hubble made the same
identification in his 1917 thesis, but gave no position for the star.
=====
NGC 396. RNGC places this object more than a degree away from Marth's
position. Yet just 5 seconds of time east of the original position is a
faint galaxy that Marth could well have seen with the 48-inch reflector.
Unfortunately, Marth rarely mentions stars near his nebulae; had he done so
in this case, the identity would have been clinched as there is a star just
10 or 12 arcsec northeast of the nucleus of the galaxy. Other than that,
however, I see no reason not to identify this galaxy as N396. The GSC
position is likely a blend of the galaxy and the star, and thus a few arcsec
northeast of the true place. However, my own measurement puts the position a
few arcsec north of the GSC position, so perhaps the GSC is OK. There is also
a faint double star at 01 05 20 +04 15.7. I doubt that this is the object
that Marth saw, but it could be. Still, I'll stick with the faint galaxy.
=====
NGC 399. See NGC 400.
=====
NGC 400, 401, and 402 are stars at Lord Rosse's measured offsets from NGC 403
and from a nearby star (his distance of N401 from N403 is an estimate,
slightly too large). His fourth nova, NGC 399, is a galaxy, also at his
measured offset. He also has a sketch showing N403, five nearby stars, and
N400 and N401, all in their correct relative positions.
=====
NGC 401 is a star. See NGC 400 for a discussion.
=====
NGC 402 is a star. See NGC 400 for a discussion.
=====
NGC 403. See NGC 400.
=====
NGC 404 is only 6 3/4 arcminutes nnw of beta Andromedae; it is often not easy
to pick up visually because of the glare of the star. This is one of the
nearest early-type galaxies, only 3.5 Mpc distant, not too far beyond the edge
of the Local Group.
See NGC 537 where this object figures peripherally in the identification of
several galaxies found the same night by WH.
=====
NGC 405 is a double star. It was found by John Herschel and is h2380 in his
Cape Observations. He has this to say about it: `[RA] 01 00 45.1: [NPD]
137 35 13 (1830.0). A star 7m? After a long and obstinate examination with
all powers and apertures, I cannot bring it to a sharp disc and leave it, in
doubt whether it be a star or not. The star B 137 immediately preceding
offered no such difficulty, giving a good disc with 320. [JH's italics:] No
doubt a "Stellar Nebula."'
I noted earlier, "JH's object is clearly a double star on the Southern Sky
Survey (was it closer together in JH's time?), and I put it in the SGC Notes
as such." However, on the DSS image, the two stars are not resolved. SIMBAD
has the separation as 1.2 arcsec at 191 degrees (measured in 1954), and has
another fainter star (component "C") at 47.5 arcsec and 81 degrees in 1913.
That fainter star is partially covered by the diffraction spike on the Schmidt
plate.
In any event, we now know why JH could not bring the star to a "sharp disc".
=====
NGC 407. See NGC 408.
=====
NGC 408, Schultz's "Nova III," is a star at his carefully measured position.
It is just 8 seconds west of NGC 410 = H II 220, which Schultz also measured.
Note that he has reversed the names of "Nova III" and H II 219 = NGC 407 in
his 1875 MN paper. Dreyer has sorted them out for the NGC, however.
Schultz's other discovery ("Nova IV" = NGC 414) in the area, is a peculiar
interacting galaxy. His position for it is excellent, as are those for NGC
407 and NGC 410.
=====
NGC 410. See NGC 408.
=====
NGC 411 is also = NGC 422, which see.
=====
NGC 412. Leavenworth has left us a sketch of this nebula, as well as the
usual poor position and brief description. Unfortunately, his sketch shows
only one star in the field, about 5 arcmin southwest of the nebula, so the
field will not be easy to recognize. The sketch is one of the few to have
the orientation marked, so that is not a problem here as it is with some of
the LM nebulae.
In fact, I can't find Leavenworth's object anywhere near his position. Nor
are there any other nebula/star pairs within several degrees of that position
that match the sketch, either. The galaxy chosen by ESO, 3.8 minutes
preceding and 19 arcmin south of Leavenworth's position does not match the
sketch, so that cannot be the object, either.
Leavenworth added a note "Neb?" to his description, so it is possible that
the object is simply a star. However, I could not even find two stars in the
correct relative orientation in the area that would match the sketch.
The sketch is dated 15 Oct 1885. Leavenworth made at least four other
sketches that same night. They are of N377, N540, N635, and N872 (all of
which see). Of these, N540's identification is unsure, and N635 is three
degrees south of its nominal position. Assuming all four identities, though,
the average offset of Leavenworth's positions in RA is +25.3 seconds of time
with a mean error of +-32.2 seconds, and a standard deviation in one
observation of +-64.5 seconds (all are at roughly the same declination, so the
conversion to arcseconds can be ignored given the size of these numbers). In
Dec, the equivalent numbers are -5.3 arcmin, +-4.2 arcmin, and +-8.4 arcmin.
Given offsets and errors of this size, and the three-degree accidental error
for N635, NGC 412 could be ANYwhere within several degrees of Leavenworth's
nominal position.
But I still can't find it. So, unless other folks want to spend more time on
the field, NGC 412 is probably irretrieveably lost.
=====
NGC 414. See NGC 408.
=====
NGC 420. See NGC 421.
=====
NGC 421 may be one of the several faint stars or wide double stars west of NGC
420. WH found the objects on 12 Sept 1784, describing them as "Two. Both
eF, vS. The following is the largest." The field was examined again by JH,
LdR, d'Arrest, and Bigourdan, none of whom found NGC 421, but all of whom
placed NGC 420 within 5 seconds of time of WH's position for the pair.
Dreyer has a curious statement in his note in the Scientific Papers (1912).
Citing the observers above as having "... seen only one nebula," he goes on
with "no doubt the following one." Yet all the observers have assigned the
preceding number (H III 154 = N420) to the object. Dreyer himself followed
JH's lead in this, giving the earlier number to the object that JH, d'A, and
LdR all saw.
In any case, there is no nebula in the area that might be N421. Since
assigning the number to one of the stellar objects mentioned above is pure
speculation, I'm not going to do it. Thus, N421 is "Not found."
=====
NGC 422 is an accidental duplicate entry for NGC 411. There is nothing at the
place of this SMC object on the sky, and the faint cluster (IC 1641) 30+
seconds of time to the east is almost certainly too faint for JH to have
picked up.
This piqued my curiosity, and I found that NGC 422 comes from JH's table of
"Stars, Nebulae, and Clusters in the Nubecula Minor" where it is number 162.
(Dreyer has correctly copied the position and class -- "III" = vF nebula --
into the NGC.) In that table, JH also has a sweep symbol in the "Zone" column
indicating that the object comes from the sweeps with the 20-foot reflector
rather than from his zone sweeps with a five-inch achromatic refractor
(IC 1641 is certainly too faint to have been seen in the five-inch). However,
no such object exists in JH's big table of "Reduced Observations of Nebulae
and Clusters of Stars".
There is, however, an entry in the "Reduced Observations ..." table, for NGC
411 (= h 2384) at just one minute of time preceding the position for NGC 422.
Furthermore, it has two positions given, the first of which has become number
157 in the Nubecula Minor table, while the second position is, as we've seen,
that for number 162 in the same table but with the RA increased by exactly one
minute of time; the north polar distance is correctly copied. It's clear,
then, that the object was accidentally duplicated in the SMC table, and
therefore eventually given two NGC numbers.
One other note: Delisle Stewart, working off plates taken at Harvard's
Arequipa "observing station" in Peru, noted for this object "Only 3 eF, sts,
close together, not a neb." Close to the position he gives (the NGC place
precessed to 1900), there is indeed a triangle of three stars. I make the
position of the center of gravity of the triangle 01 07 06, -72 02.0 (B1950).
I'm not certain that these are the stars that Stewart was referring to, but it
seems likely. In any case, I don't believe that Stewart's note helps in
locating NGC 422, but wanted to mention his remark so that it causes no future
confusion. (Note, too, that Stewart has another faint cluster just a minute
of time on east of his three stars -- this is IC 1641 [which see], a separate
object with a story of its own.)
=====
NGC 430. See IC 85.
=====
NGC 443 = IC 1653. D'Arrest has a single observation of the galaxy from the
night of 8 October 1861. He published it in AN 1500, and again in his big
monograph. The declination is 0.5 arcmin greater in the monograph, but it is
still nine arcmin too small. I suspect a digit error in the arcminute 10's
place. With that, the position would be within an arcmin or so of the true
position. D'A's note about the 15th magnitude star 8.3 seconds of time
preceding the galaxy is correct -- the actual distance is 7.9 seconds.
Javelle rediscovered the galaxy over 40 years later in 1903. His micrometric
observation, re-reduced with respect to a modern position for his comparison
star, is within a couple of arcseconds of the modern positions.
=====
NGC 444 = IC 1658. Lord Rosse discovered NGC 444, observing it on four
separate nights. He placed it roughly five arcmin west of NGC 452, but did
not make any micrometric measurements of it. The NGC position is probably
from Dreyer himself, and is about 30 seconds west of the actual position. The
identity is secure, however -- the galaxy and surrounding star field are
exactly described by LdR and his observers.
Javelle's position for IC 1658 is within a few arcsec of the GSC position, so
the identity of this object is also secure. Javelle's comparison star, BD
+30 192, is, not coincidentally (it is the brightest star in the area),
mentioned by Lord Rosse who notes that NGC 444 is about twice as far from NGC
452 as the star.
=====
NGC 446 = IC 89. Found by Marth in 1864, this is one of his objects that he
"verified" -- that is, reobserved. Nevertheless, his RA (and therefore, the
NGC's) is just one minute of time off the true position. This is probably a
transcription or typographical error. The declination is within an arcminute
of being correct, however. IC 89 has a good micrometrically measured position
in IC1 from Javelle's first list.
RNGC has suggested that UGC 794 is NGC 446. That galaxy, though, is
considerably fainter than the real N446, and its position is off by odd
amounts from Marth's: 13 seconds of time, and 7 arcminutes. That identity is
therefore unlikely.
=====
NGC 447 = IC 1656. This is misnamed "NGC 449" in CGCG, and that has
unfortunately carried over into several other catalogues. The galaxy was
found by d'Arrest who observed it on four different nights, each time
measuring its position with a micrometer. His position is good, as is his
description, especially concerning an 11th magnitude star 9.2 seconds of time
east and 110 arcseconds north of the nebula -- the star is there, so the
identification is secure.
IC 1656 was found about 40 years later by Barnard. Since this is one of the
nebulae which he "published" in a private communication to Dreyer, we have
only the position and description in the second IC to guide us. His RA is
good, but the declination is about 1.4 arcmin north of the galaxy. His
description is similarly confused, "Neb, S * close sf, *9 sf 3 arcmin." The
"S * close sf" is indeed superposed on the southeastern edge side of the
galaxy (the GSC position is a blend of this and the galaxy), but the "* 9 sf
3 arcmin" is actually northwest by three minutes. It is the same star that
d'Arrest called 11th magnitude. Still, the are no other galaxies in the area
with quite that arrangement of stars around them, so Barnard's object is
certainly the same one that d'Arrest had seen earlier.
See NGC 451 = IC 1661 for more about Barnard's observations in the area.
=====
NGC 449. Mislabeled "NGC 447" in CGCG, this galaxy (Markarian 1) has had
its incorrect name unfortunately carried over into several other catalogues.
There is, however, no doubt as to the correct number as the NGC position (from
a micrometric measurement by Stephan) is within a few arcsec of the GSC
position. This is the first of three new "nebulae" in the area that Stephan
found late in 1881 using the large refractor at Marseille. The other two are
NGC 451 and NGC 453, both of which see for more information.
=====
NGC 451 = IC 1661, and is another of Barnard's IC discoveries sent directly to
Dreyer (Stephan discovered the object, and his observation led to the NGC
entry). It is also the second of two nebulae which Barnard found in the area.
Like the first (NGC 447, which see), there is possible confusion about its
identification. In this case, Barnard's description is sparce, "eF, S, R"
and his position has the RA of NGC 451, but is closer in declination to NGC
449.
Two things convince me that Barnard reobserved NGC 451 (which is just where
Stephan measured it to be): 1) this galaxy is brighter than N449 by at least
a magnitude, and it is larger, too. 2) Barnard's declination is about 1.2
arcmin north of the true place of NGC 451, just as his declination of N447 is
about 1.4 arcmin north of that galaxy. If he observed both objects on the
same night, as seems likely, then the offset will be systematic. Since we
know the identification of N447 = I1656 is solid, it follows that N451 must be
I1661.
=====
NGC 452. See NGC 444.
=====
NGC 453 is a linear triple star found by Stephan. The stars are exactly where
Stephan measured them to be, and his description mentions "one or two" vF
stars involved. On a night of less than perfect seeing, the three stars must
indeed resemble a faint nebula laced with even fainter stars.
=====
NGC 456. See NGC 460.
=====
NGC 460 is the second of at least three HII regions/stellar associations in
the SMC. JH's position coincides with a bright knot on the southern edge of
a nebulous mass with several bright stars nearby. I've taken this as the
object that JH saw.
About 2 arcmin southeast is another double-lobed nebula involved with many
stars. JH does not have any entry in his CGH list that corresponds to this,
though it should have been bright enough for him to pick out.
Other objects in the area that he saw include NGC 456 (similar to N460, but
larger), NGC 465 (a stellar association without nebulosity), and h2398 (not in
the NGC) which JH places 2 minutes of time west of NGC 460 where there are no
nebulae or clusters he could have seen.
His description makes this last object sound like it is NGC 460, but it could
be NGC 456 with a one minute error. Here is what he had to say about it:
"Chief centre of condensation at southern edge of an irreg[ularly-] figured
nebulous mass 2' diameter." Since he saw this in one of the same sweeps in
which he picked up NGC 460, I'm inclined to believe that this is NGC 456 with
a one-minute error in the RA. JH may have come to the same conclusion. There
is certainly no note in either GC or NGC that mentions the missing CGH object.
=====
NGC 464 is clearly just a double star (see the 2MASS J-band image, and the
SDSS g-band image), though I noted it earlier as (first) a double, then as a
triple. I should have just left well enough alone ...
Here is the historical note. Though credited to Tempel (in his fifth list of
observations of nebulae), it was actually found by the BD observers as they
swept the field. Tempel has only this to say about it: "Im Atlas vom
Argelander einen kleinen neuen Nebel verzeichnet in: 01 11 25, +34 12" [In
Argelander's Atlas, there is a small, new nebula plotted at ...]. Since the
BD was made with a 78-mm refractor, Argelander's observer could not have seen
the faint galaxy fingered by RNGC.
-----
Checking the BD (both the original version from Bonn in 1903, and the ADC's
1993 publication of their digitization), I do not find the "nebula" -- or
indeed any star -- at the position given by Tempel. Dreyer made the same
assumption -- that the object was from the BD with an equinox of B1855 -- when
he precessed the position given by Tempel. The nebulae shown on the BD charts
may not be listed in the catalogue itself.
Brian Skiff tells me that Lowell Observatory's 1954 "Third Corrected" edition
of the BD charts does not show the nebula. So, we need to dig out earlier
editions -- preferably the first edition from the 1860s -- to check further on
this.
Brian additionally sends along some data for the double star, apparently an
optical pair: the combined V magnitude is 12.1, pretty faint for the BD
observers, but not unheard of. The position angle and distance of the two
stars is changing slowly and smoothly from 334.8 deg, 8.98 arcsec in 1947.86
(AC2000) to 336.6 deg, 10.13 arcsec in 2015.0 (Gaia DR1).
=====
NGC 465. See NGC 460.
=====
NGC 468 is not IC 92, as I have long supposed. Courtney Seligman wrote in
March 2015 suggesting that the NGC object might be identical with NGC 472, a
brighter galaxy than IC 92, and at the same declination.
After looking at JH's Sweeps for a day, I wrote back to Courtney, "The short
answer is that you're right: NGC 468 is almost certainly a second observation
of NGC 472."
Here is a somewhat condensed version of the longer answer:
At first, I was as puzzled as you were by the fact that JH had apparently
swept up a fainter galaxy instead of a brighter one. But this is indeed
possible because of the way that both Herschels swept the sky -- they used
their telescopes as meridian instruments, "sweeping" north and south in
short arcs of typically 2.5 to 3 degrees, while the diurnal motion carried
the sky westward across the meridian through their field of view. It's
possible to miss objects if the north-south arcs are too long and the
diurnal motion carries the sky too far west. I thought that this might have
happened here. Wolfgang Steinicke has found cases in William Herschel's
sweeps where it actually accounts for missing nebulae.
With this kind of sweeping, errors in RA are just as likely as those in Dec.
Indeed, in both the Herschels' observations, there are many RA errors of not
just digits (e.g. 1 minute, 10 minutes, etc), but of seemingly odd amounts
like 18 seconds, 46 seconds, and other strange numbers. That's the case
here where, as Courtney noted, the Dec is correct for N472, but the RA is
off by 37 seconds.
This inspired me to dig into JH's Sweep 106 on 22 November 1827. I did a
rough "reduction" of his observation w.r.t. one of the stars in the sweep,
sigma Trianguli. That got me to within a few arcminutes of the position in
the NGC, but not close enough to really verify JH's position. So, I had to
ask how he did his reductions, a question that I've been curious about, but
never had to answer before. (JH, by the way, describes his reduction
technique in detail in one of his early papers on double stars. This paper,
unfortunately, does not seem to be currently on-line.)
After reading through many of his early sweeps -- which are preserved in a
"fair copy" up to Sweep 107 so they are more legible than the actual
observing logs -- I worked out what the entries in the logbooks mean. Here
is the observation of NGC 468:
01 12 45 -29 2 01 10 00
The first three numbers are a clock or watch reading, the 4th is a count on
a chronometer ticking off 130 (*not* 120) "beats" per minute, the fifth is
the eyepiece wire -- there were two of them (though JH also occasionally
used the trailing edge of the eyepiece field as a third "wire") with which
he timed the meridian passage, and the last three numbers are the NPD
"index" on a scale marked in degrees, minutes, and seconds of arc.
To reduce the RA, JH applies various corrections to these measurements, the
main ones being the clock correction for each wire, along with the
difference between the transit and the count of the chronometer "beat."
(All this, incidentally, must have been recorded by JH's assistant, usually
John Stone, finally mentioned by name in the Cape of Good Hope Observations,
so that JH would not have had to ruin his night vision.) The clock
corrections, as well as the index zero points are worked out by using known
star positions, of course. For this sweep, JH has clock corrections of
-1m 37.0s for wire 1, -2m 13.5s for wire 2, and -2m 45.9s for the trailing
edge of the field. Applying the number for wire 2, along with 13.4 seconds
for the 29 chronometer "beats" to the 01 12 45 clock reading gives an RA of
01 10 18.1 for the date of observation (in this case, JH simply took 1828,
close enough given his usual accuracy).
Similarly, the mean NPD zero point is +57d 02' 36" for the sweep, so the NPD
is 58 12 36, again for epoch 1828. JH then precessed this to 1830 with his
precession tables (which I haven't uncovered yet), but using the modern
precession, these come close to the numbers that JH included on his
reduction pages, that he copied into his published papers, and that Dreyer
eventually copied into the NGC.
Going through the reduction again shows that there is no large error in JH's
calculations or the resulting positions, in either RA or NPD.
But, looking at the log, I noticed that the "2" notation for the wire number
appears to have a "1" written over it. It's not very clear, and could well
be the result of the photocopying process as the RAS people were copying the
page for the Herschel Archive. But the "-29" has a similarly overstruck
"2", so I wondered what would happen if the wire number actually was "1" and
not "2". Going through that reduction gave me the RA as 01 10 54.6, with the
same NPD, 58 12 36, for 1828. This becomes 01 20 30.2, +32 41 45 for J2000.
Compare this with the modern value of 01 20 28.7, +32 42 33 from UCAC for
NGC 472 -- there it is.
So, it looks to me like the wrong wire was recorded in the Sweep. If this is
the only mistake, it seems reasonable to simply adopt JH's published position
and correct it by the +36.5 seconds of time between the first and second wires
at the same declination. The agreement in position between the two
observations is even closer with this easy fix.
All this makes additional sense if JH actually saw the brighter NGC 472 rather
than the fainter IC 92. We can't be absolutely sure that this is the correct
explanation, of course, but this looks like another kind of "digit error" that
could happen fairly commonly. I will re-examine other of JH's apparent RA
errors to see if the same reasoning can recover other "lost" or misidentified
objects that he observed. (A couple of additional cases of possibly mistaken
wires are the clusters NGC 6396 and NGC 6400, both of which see. Their
identifications are not in doubt, but the RA's are off.)
=====
NGC 469. See NGC 475.
=====
NGC 471. See NGC 475.
=====
NGC 474 is an example of a "shell" galaxy, perhaps the result of a merger of
two or more individual galaxies. See Turnbull, Bridges, and Carter, MNRAS
307, 967, 1999 for a recent photometric investigation of this object.
=====
NGC 475 = IC 97. Marth discovered three galaxies here (NGC 469, 471, and
475), and his positions are pretty good. Two of his positions got changed for
the NGC, however -- for the worse. Dreyer credits Peters for N475 as well as
Marth, and it is apparently Peters's position which throws off the NGC.
Marth's original position is within a minute of Bigourdan's measured place for
IC 97, so the identity is certain. The object which Bigourdan calls N475 is a
star near the incorrect NGC position.
=====
NGC 480. The identification is not quite sure since there is no sketch of the
object and its field. Nevertheless, the faint galaxy I've assigned the number
to is not too far from Leavenworth's position, and matches his description.
-----
Note, too, that Leavenworth's RA is east of his RA for NGC 481 (which see), a
brighter galaxy about 45 arcminutes to the northeast. Even though his
relative declinations, sizes, and magnitudes are correct, his RAs are not.
Fortunately, Swift (and later Howe) picked up the brighter object, so it has a
good position. This does, however, switch the order of the two objects in the
NGC compared with the Leander McCormick list, a potential source of confusion.
=====
NGC 481. The stars that Leavenworth describes in his Note, "*12.5, np 1';
*12, nf 2'" are just where he says they are, and his position is not too far
off. As with NGC 480, there is no sketch, but the description of the star
field is clear and correct, so there is no problem with this identification.
On 20 November 1886, Lewis Swift also picked up this object. He noted a "F *
nr np"; this must be the first of the two stars that Leavenworth mentions.
Even though Leavenworth's place is not too bad in this case, Swift's is a bit
closer to the galaxy. This was fortunate as Dreyer adopted Swift's position
for the NGC.
Finally, in the first of his Monthly Notices articles (MN 58, 356, 1898),
Herbert Howe provides a micrometrically measured position that Dreyer included
in the IC2 Notes. Howe's place is within a few arcseconds of the modern
position for the galaxy.
=====
NGC 483. See NGC 499.
=====
NGC 486, about 5 arcmin north-northwest of NGC 488, is a compact galaxy with a
faint star superposed on its eastern side. LdR's sketch is accurate, as are
his offsets.
=====
NGC 488. See NGC 486.
=====
NGC 490. See NGC 492.
=====
NGC 492 has a somewhat fainter companion about an arcmin southwest. LdR does
not mention two objects here, and his micrometric offset of N492 from N490 is
exactly on the brighter object, so there is no possible confusion of
identities here.
=====
NGC 495. This is one of three -- the others are NGC 496 and NGC 499 -- that
WH found on the night of 13 September 1784, and for which he measured only a
single position. In the fair copy of the sweep, he (or CH?) comments in
parentheses, "I believe the time should be -,5". If this is so, then the RAs
should be 30 seconds of time less than he entered. This, however, would put
his position 30 seconds of time west of the galaxies; his published offsets
(from beta And) are very close to being correct as they are. So, we can't do
much about his suggestion of an uncertain time aside from noting it. At least
he flags the RA with double colons in the sweep, though he did not carry that
uncertainty over into the published paper.
For more on the field around beta And, and the uncertainties in WH's data
there, see NGC 499 and NGC 537.
=====
NGC 496. This is a companion to NGC 495 and NGC 499 (see both of these for
more), also found by WH. He measured a single position for the three objects,
and flagged the RA offset with double colons in the sweep. Those colons did
not make it into his published list.
=====
NGC 498 is the object labeled "D" in the first two of LdR's diagrams of the
group around NGC 499. Though he has no measured offsets for it, he clearly
saw it the second night: "vvF, but certain" and the diagrams leave no doubt
as to the correct object.
=====
NGC 499 = IC 1686 is the brightest of a moderately compact group of galaxies
in a cluster of which NGC 507 is the dominant member. It, with six others in
the cluster, was found by WH (see NGC 495 for a bit more on WH's observation
of NGC's 495, 496, and NGC 499, which he treated as a triplet with a single
position). JH reobserved five of the six, but mislabeled a "nova" (NGC 483)
as the first of his father's objects (d'Arrest makes the same mistake). Lord
Rosse has observations on 8 different nights, and -- with the exception of NGC
483 in the first observation -- got the identifications correct. Schultz also
got the correct objects, and Dreyer sorted the field out well for the NGC.
Javelle swept over the field late in 1899, finding and measuring a dozen
objects in the area that he took to be previously uncatalogued. However, his
accurate position and exact description of one of those "novae" points
directly at NGC 499 -- in spite of the fact that he has a footnote on the
object saying that "NGC 499 was also measured." He has clearly misidentified
the object in the crowded field. Since he unfortunately does not publish his
measurements of the NGC objects, we cannot now be sure just which galaxy he
mistook for NGC 499. Dreyer did not catch Javelle's error (Javelle's absolute
declination is about 1.7 arcmin off since he used the BD position, also 1.7
arcmin off, for his comparison star), so the galaxy now carries the IC, as
well as the NGC, number.
=====
NGC 506 is a NOT the star just over an arcmin southwest of NGC 507 that I
mistakenly fingered years ago. I finally reduced Dreyer's micrometric
measurements (made with the 72-inch at Birr Castle in November 1874), and
found that the star is the preceding, and slightly brighter, of a pair.
Dreyer's position is about a second of time off the star, but nearby galaxies
have the same offsets in his measurements. I'm not sure now what led to my
misidentifying the star in NGC 507's corona, but it is certainly NOT NGC 506.
The remainder of my earlier note, however, is more or less correct:
It was found and its offsets measured on one night by LdR. The offsets are
good and the identity is sure.
This statement obviously now applies to the correct star, finally identified.
My apologies!
=====
NGC 507 is the brightest of a relatively poor, though nearby cluster of
galaxies. There are several notes about the area; see e.g. NGC 499 = IC 1686,
and NGC 506.
=====
NGC 510 is a double star found by Schultz. His micrometrically measured
position is within a few arcseconds of being correct. There are no other
objects that he could have seen within two arcminutes of his position, so the
identity is secure.
=====
NGC 513. This is one of the galaxies that WH found the night of 13 Sept 1784.
This, along all but one of the others, have poor positions in NGC. RC3
managed to get the correct position, however. See NGC 537 for the story.
=====
NGC 515. See NGC 537.
=====
NGC 517. See NGC 537.
=====
NGC 520 is apparently an interacting galaxy. Classified as an I0 by de
Vaucouleurs, the distorted dust lane and unresolved bulge with plumes may be
the result of a collision. Vorontsov-Velyaminov marks three components in his
Atlas of Interacting Galaxies; I've provided positions for them in the table.
However, in the near-infrared, the structure is simpler with a bright peak at
the center connected by a bridge to a somewhat fainter knot to the northwest
(this fainter knot has no optical counterpart). The central peak breaks up
into at least three hot spots in the 2MASS J-band. The J2000.0 positions are
Central peak, K-band: 01 24 34.89 +03 47 30.1
Central peak, H-band: 01 24 34.86 +03 47 29.9
Central peak, J-band: 01 24 34.86 +03 47 28.3 southeast spot
Central peak, J-band: 01 24 34.65 +03 47 35.0 northwest spot
Central peak, J-band: 01 24 35.04 +03 47 33.1 northeast spot
Northwestern knot: 01 24 33.33 +03 48 02.8
The southern of the three optical components (VV 231b) corresponds most
closely to the position of the infrared/radio nucleus.
=====
NGC 523 = NGC 537, which see. Also see NGC 5765 for a note on objects noted
as double by WH or JH yet given just a single position.
=====
NGC 529. See NGC 531 and NGC 537.
=====
NGC 530 = IC 106, which see. Also see IC 1696 which is a different galaxy.
=====
NGC 531 and NGC 542 are positively identified by LdR's sketch and offsets from
NGC 536. However, Dreyer, apparently thinking that NGC 529 was the bright
object reobserved by LdR, used an incorrect position for the reference object.
So, the positions he gives in LdR's 1880 paper, and in the NGC, are off by
about 40 arcsec.
=====
NGC 534. See NGC 549.
=====
NGC 536. See NGC 531 and NGC 537.
=====
NGC 537 = NGC 523, and the surroundings. The night of 13 September 1784 was
not a good one for WH's clock readings. With one exception (H II 224 = NGC
404), all eight objects for which he used Beta Andromedae as a comparison star
are off in RA, and -- as it has turned out -- by different amounts. In the
sweep, which I finally got to in July 2016, WH noted uncertainty in the RAs of
five of the objects (NGC 495, 496, 499, 515, and 517), and recorded transit
times for four others (NGC 515, 517, 536 and 537) only to a full minute of
time (Dreyer, as we'll see below, was well aware of all of this). In
addition, his descriptions -- with a few exceptions -- are scanty, so
identifying his nebulae has proved problematical over the years. Here is the
story, roughly in chronological order, as I first presented it years ago.
Note that Wolfgang has recently (July 2014) reanalyzed the field in light of
WH's sweeping path; a summary of his results is at the end of this note.
WH's seven questionable objects (III 167 through III 173; NGC 515, 517, 513,
523, 536, 552, and 553, respectively -- yes, NGC 513 is out of order) all
appeared in his sweep within 3 minutes of each other. Given the rush, he
determined the positions for only five of them, lumping four together into two
pairs, and treating the remaining three individually. In addition, Dreyer
(as I pointed out above) noted that WH recorded three transits -- III 167/8,
170, and 171 -- to only a full minute of time. Finally, WH himself noted the
final two as "a little doubtful." Of all this uncertainty, only that phrase
made it into WH's first catalogue of nebulae where these were presented.
JH has only five nebulae here. He claimed one (h120) to be the same as his
father's III 171, and the western of that pair (h118) to be a nova. Auwers,
and later d'Arrest, agreed with JH in making H III 171 = h 120, but noted the
difficulties in WH's RAs for some of the nebulae. d'Arrest in particular
pointed out discrepancies of about 40 seconds of time between his own RA's and
WH's in several cases, and found what he thought was a new double nebula in
the field (NGC 523).
However, while assembling the GC, JH reinterpreted the field and chose to
regard the nebulae that his father discovered as separate objects from his
own. Dreyer, too, was aware of the problem when he compiled the NGC, and
attempted to sort things out based primarily on d'A's observations. It's
clear, however, that he was a bit uncertain about the state of the field as
he wrote NGC notes for some of the objects, and commented again on all of them
in his 1912 edition of WH's Scientific Papers.
How can we make sense out of the two Herschels' observations? Let's start by
assuming that WH's nebulae are properly ordered by RA, and that their polar
distances (Declinations) are also relatively correct. Doing this, and looking
at JH's and d'A's later observations, we can make some tentative
identifications for NGC 513, 515, 517, and 536. Plotting the difference in RA
(WH minus "true") for these, we see that as the time went on, WH's RA's got
worse. Plotting a straight line through the data points, and putting a mark
at WH's RA for III 170 = NGC 537 suggests an RA correction of about 0.9
minutes of time for it. This moves the RA back to within 0.2 arcmin of NGC
523, and confirms Dreyer's suspicion in the NGC Notes that WH's number belongs
on this NGC number.
Adding this point to the plot actually suggests that the slope might be even
steeper. But what about N536 = III 171? Did WH really see that, or did he
perhaps see its brighter, higher surface brightness companion, N529, which
precedes it by about 40 seconds? (N536's two fainter companions found by Lord
Rosse, N531 and N542, have problems of their own; they have a seperate note
here under N531). Assuming WH in fact did see the western of the two objects,
we can then draw a new line through the points on the plot (this steeper
relationship suggests that WH's clock was running at about half speed, which
it, of course, was not!) in a desperate attempt to recover his final two
objects, N552 and N553. If we correct WH's RA accordingly, the position of
these two objects falls close to CGCG 502-084 and an equally bright 15th
magnitude star just west of it.
Finally, I note that -- with the exception of NGC 513, the first object in the
series -- all of WH's declinations here are 3-4 arcmin too large. Correcting
those puts his positions near enough the galaxies I've noted in the table
below. This lends a bit more support to the hypothesis I've sketched out.
In the end, then, I'm suggesting these identifications for the nebulae in the
area (the CGCG names added for verification):
RA (2000.0) Dec NGC WH JH d'A CGCG
III WH JH
01 24 26.81 +33 47 58.2 513 169 111 --- --- 521-020
01 24 38.50 +33 28 21.8 515 167 113 167 113 502-077
01 24 43.80 +33 25 46.5 517 168 114 168 114 502-079
01 25 20.76 +34 01 29.9 523=537 170 --- (Nova) 521-022
01 25 40.29 +34 42 46.8 529 171 118 --- 118 521-023
01 26 21.76 +34 42 11.1 536 --- 120 171 120 521-025
01 26 10.01 +33 24 20.5 552 172 --- --- --- --- = *
01 26 12.52 +33 24 18.5 553 173 --- --- --- 502-084
The careful reader will have already seen that the RA's for N552 and N553 are
smaller than that for N536. This adds more weight to the idea that Herschel
saw N529 rather than N536.
A postscript: Both Auwers and d'Arrest comment on WH's insecure RA's for
these objects. However, d'A apparently goes on to suggest that some of JH's
RA's are off, too. But they aren't, so I clearly need to take the time to
translate d'A's comments (that remains to be done as of July 2016).
-----
There it stood until the summer of 2014 when Wolfgang went back to CH's fair
copy of the sweep and reanalyzed it, making careful and justified assumptions
about WH's sweeping methods related to the size of his field through his
eyepiece. Rather than suggest a clock running at the wrong rate, Wolfgang
showed that the crowding of the nebulae contributed to several inexactly
recorded times. His detailed report will appear in his forthcoming book on
WH's nebulae, but his conclusions are as follows:
RA (2000.0) Dec NGC WH JH d'A CGCG
III WH JH
01 24 26.81 +33 47 58.2 513 169 111 --- --- 521-020
01 24 38.50 +33 28 21.8 515 167 113 167 113 502-077
01 24 43.80 +33 25 46.5 517 168 114 168 114 502-079
01 25 20.76 +34 01 29.9 523=537 170 --- (Nova) 521-022
01 25 40.29 +34 42 46.8 529 --- 118 --- 118 521-023
01 26 21.76 +34 42 11.1 536 171 120 171 120 521-025
01 26 57.0 +33 33 28 552 172 --- --- --- --- = *
01 27 03.0 +33 32 55 553 173 --- --- --- --- = **
Note that only two of the NGC identifications are changed from my initial
sorting out, and that only one of the WH numbers had to be moved for this
particular group of nebulae.
Wolfgang also looked closely at other of the Herschels' nebulae in the area.
I'll comment on those as needed.
=====
NGC 539 = NGC 563, which see.
=====
NGC 540 is one of the 170 or so nebulae found at Leander McCormick in the
mid-1880s to have a sketch. Unfortunately, the sketch shows only one star in
addition to the nebula. However, that field is fairly well matched by ESO
542- G012 1 minute and 50 seconds east and about 5 arcmin south. I've taken
that as a tentative identification for N540.
See NGC 412 for another LM nebula with a sketch that did not work out so well.
=====
NGC 542. See NGC 531.
=====
NGC 544. See NGC 549.
=====
NGC 546. See NGC 549.
=====
NGC 549. Steve Gottlieb has suggested that the SGC and ESOB identification of
this galaxy is incorrect. He is almost certainly right, in spite of the poor
right ascension from John Herschel (18 seconds of time off); Herschel's
declination is correct, though. The ESO/SGC galaxy is 15 arcminutes south and
4 seconds of time east of Herschel's position. Though this is brighter, it
does not match Herschel's description ("eeeF, S, R, vgbM. The 4th of a group
of 4."). Instead, this matches very closely what I'd expect him to see based
on his descriptions of the other three galaxies in the group (NGC 534, 544,
and 546, all "eeF, S, R, vgbM"). Accepting Steve's identification, the only
error is in Herschel's RA.
For each of the other three galaxies, Herschel has two observations, but only
lists one for N549. There are no significant zero point offsets in the
differences between the raw positions for the other three galaxies. This
means that we have no reasonable way to "correct" the original position of
N549 as given by Herschel. This in turn means that we are left with only the
description to help us identify the galaxy. And that points directly to the
object which Steve (and the original ESO list 5 in A&AS 31, 15, 1978) chose as
NGC 549.
-----
The object occurs in JH's Sweep 803 on 30 Nov 1837, where it is number 13. JH
has four nebulae here observed in pretty rapid succession: NGC 534 (which he
calls "N1"), NGC 544 ("N2"), NGC 546 ("N3"), and NGC 549 ("N4"). He noted the
position of NGC 549 with respect to NGC 546: "fols 3 15[sec] +-" and "3' north
of 3". While JH's estimated RA is off -- but note his "+-"! -- his relative
NPD is correct for Steve's object. So, there is no doubt that it is the right
one, that SGC is wrong, and that Andris Lauberts in his ESO list 5 is also
correct. I suspect I sent him the "correction" before ESOB was published, and
he followed my "advice". My apologies to all!
=====
NGC 551. See IC 1707.
=====
NGC 552 is probably a star. But is it the one I point to just northwest of
CGCG 502-084? Wolfgang suggests that it is a different star (or perhaps a
double star), but does not identify it in the preliminary analysis of the
field that he has so far circulated (July 2014). Details will probably be
presented in his forthcoming book on WH's observations. See NGC 537.
=====
NGC 553 may be CGCG 502-084. However, Wolfgang believes that galaxy lies
outside of WH's field in the sweep, and suggests instead that WH's object may
be a single or double star. See NGC 552 and NGC 537 for more.
=====
NGC 557 = IC 1703. NGC 557 comes from Swift's 6th list, sent in pieces to
Dreyer before it was published in AN 2798. The final published description
reads: "eF, S; B * f 15 seconds and is n of it." This differs a bit from the
NGC description: "eF, S, R, * 10 nf," but not in any significant way. The
star is actually southeast, but the galaxy is still almost uniquely identified
by that star. Swift's RA is nearly 50 seconds of time out, and I wonder if he
made a 1 minute error in reading his circles -- a 10 or 12 second error is
somewhat closer to his usual accuracy.
Bigourdan did not find N557 when he looked for it at the NGC place, but he did
run across it a few minutes later. Thinking it was a "nova," he listed it as
new and it ended up in the IC2 at its actual position.
=====
NGC 558 is not equal to IC 117, which see.
=====
NGC 559 is a fine open cluster seen by both WH and JH, though JH's NPD is one
degree too far south. It has a "core/halo" structure, with the corona being
composed of generally fainter stars. This may simply be an effect of patchy
Galactic extinction, but I've given the diameters and positions for both the
inner and outer parts of the cluster.
=====
NGC 560 is identical to IC 117, which see.
=====
NGC 563 = NGC 539. Leavenworth's description for NGC 563, particularly his
comments "little extended 0 deg" (which applies to the bar) and "several
faint stars following, in line north and south" exactly describes another
discovery of his, NGC 539 (which he sketched; the star field around the galaxy
matches the POSS1 star field). The position for NGC 563 is two minutes too
far east, a common error in the Leander McCormick lists.
Unfortunately, there is another galaxy about half a degree south of the poor
position in NGC that has been taken by all the modern cataloguers (including
me in SGC and the early versions of SEGC) as N563. However, the description
just does not fit the object, and declination errors are far more unusual in
the LM lists than RA errors. The identity with N539 is secure.
=====
NGC 564. See IC 117.
=====
NGC 568 = IC 1709, which see.
=====
NGC 575 = IC 1710. The 2 degree error in declination is one of the few errors
that can be traced to Dreyer himself. Entering this object in his 1878 GC
Supplement, he miscopied the correct "69" (degrees of NPD from Stephan's 8th
list) as "67". (It is also possible that the typesetter made a typographical
error. If so, Dreyer did not catch it during proofreading.) He later
transferred this exactly to the NGC, so it too has the incorrect degree of
NPD.
When the correction is made, the galaxy turns out to be the same as IC 1710,
found and measured by Javelle. Had the NGC the correct position, Javelle no
doubt would have not included the galaxy as a discovery of his own. Dreyer,
of course, transcribed the position correctly the second time around. The
equality was first noticed by Reinmuth, and mentioned by him in "Die Herschel
Nebel" of 1926.
=====
NGC 577 = NGC 580. Tempel claims to have found two nebulae 2m 50s following
NGC 560 and 564, a pair found by WH. There is only one here, and it was also
picked up by Swift in 1886 (more below) and, even earlier on 23 October 1867,
by A. N. Skinner at Dearborn Observatory (see IC 1528 for that story).
Tempel's position for it, apparently from a letter to Dreyer -- the position
in his first paper on nebulae is about two arcmin off the NGC position -- is
not bad. In particular, the NGC RA is less than two seconds of time off.
Curiously, Dreyer also credits Tempel's second paper for this first nebula. I
find no mention of it there, so suspect that Dreyer simply noted the wrong
paper number. I'll check the rest of Tempel's papers to see if it is in fact
mentioned in any of them.
The second of Tempel's nebulae is probably one of the stars in the area, but
since he gives the position with a precision of only 10 seconds of time and
10 arcminutes, we have little hope of recovering his object (Dreyer adopted
Swift's position for this object). There are two stars northeast of the
galaxy, though, that are similar in brightness to others that Tempel mistook
for nebulae (see e.g. NGC 4315 and NGC 4322). One is at 01 28 12.05, -02 13
01.0; and a second somewhat brighter star is at 01 28 19.78, -02 12 20.3 (both
positions are for equinox B1950.0).
As I mentioned above, Swift also picked up the galaxy, on the night of 20
November 1886. Since he made his RA 23 seconds larger than Tempel's, Dreyer
believed that this was the second of Tempel's nebulae. So, he adopted Swift's
position. Howe published a corrected RA in 1900, but has no other notes on
the galaxy. Neither he nor Dreyer, who published Howe's correction as an IC2
Note, noticed that that made Swift's object, NGC 580, identical to NGC 577.
Some observers might want to put one of these numbers onto one of the stars
I've noted. But that number would be the following of Tempel's two, the one
with the imprecise position -- and that is the one that Dreyer used for
Swift's object. And we do not know for sure which star, if either, is the one
seen by Tempel.
So the easiest, and still a truthful, solution is to simply say that Tempel's
one real nebula is identical to Swift's.
-----
Looking at the field again in April 2017, I see that the only other galaxy in
the area anywhere bright enough for Tempel to have possibly seen is IC 126.
However, that is nearly a full minute of time west of NGC 577, so is unlikely
to have been Tempel's second nebula. I've not even listed it in the main
table as a possibility, but feel compelled to mention it here if someone else
wants to follow up on it.
In the earlier discussion above, I did not give Tempel's positions or notes.
Here they are, translated by me with Google's help (the positions are for
1855):
01 23 23 -02 46 } Near the star Lalande 2666, which has in its field
} the nebulae III 441-42, are still two more nebulae
} following by 2m 50s, one as bright as the preceding
01 23 2... -02 4... } of Herschel's.
He gives no discovery dates in this table, though his paper is dated May 1878,
so the date must have been earlier than that. For the position table, I've
precessed the second of Tempel's positions as if it were given "01 23 25,
-02 45". As I mentioned above, Dreyer adopted Swift's position.
I also found the second reference to NGC 577 in Tempel's 4th paper (AN 2347).
Here he gives a more precise position for a single nebula and comments,
"II class, somewhat brighter than the two preceding nebulae, H III 441, 442
[NGC 560, 564]." Tempel gives the discovery date as 14 August 1877, and the
date of measurement as 14 November 1879. Wolfgang had also found this
observation during his work on his 2010 book, and adds, "Because there is only
one object at Tempel's place (13-mag galaxy), his first observation was
erroneous; thus we have NGC 577 = NGC 580. Thus, Aron Skinner (Dearborn
Observatory) was the true discoverer."
That pretty succintly sums up the situation, though I would point out that
Tempel did in fact see at least one galaxy in 1877, so his first observation
is not completely "erroneous". I find it rather curious, though, that he did
not mention the second nebula in his 4th paper, even to correct his first
observation.
=====
NGC 580 = NGC 577, which see.
=====
NGC 584 = IC 1712, which see.
=====
NGC 586. See IC 1712.
=====
NGC 587 is not IC 1713, which see.
=====
NGC 603 is a triple star found by Lord Rosse or by his observer, Bindon
Stoney, on 29 November 1850. Its position was unfortunately not
well-determined, so there has been some puzzle over its identity. Dreyer, in
the Notes to IC1, claimed that he could only see a faint star in the place of
NGC 603. (I've been unable to identify this star with any certainty. One
candidate is at 01 31 30.4, +29 55 58, B1950.0, while Bigourdan has two
observations of another at 01 31 44.7, +29 56 42.)
However, Lord Rosse's description makes the identification certain, even
without a good position: "A S neb or Cl with 3 sts in it. It is about 8' ssp
a ** whose components are of the 11 m." This is very close to the actual
distance of the double from the triple star -- but there is no nebulosity or
cluster associated with the triple. I suspect that the discovery was made on
a night of relatively poor seeing, leading to the impression of accompanying
nebulosity.
The B1950.0 positions of the three stars, all from GSC, are
*1 01 31 54.54 +29 58 37.1 = GSC 02293-00972
*2 01 31 54.85 +29 58 45.4 = GSC 02293-00966
*3 01 31 55.37 +29 58 31.6 = GSC 02293-00998.
I've adopted the mean value for the main table.
-----
Since I wrote that decades ago, SDSS and Gaia DR1 have become available. Both
have four stars here, and the SDSS image clearly shows that the southeastern
star is actually double, with the southeastern component of that being quite
red while the northwestern component is blue (the other two stars of the
"triple" are blue as well).
So, I've recalculated the mean position for the asterism, this time using all
four stars with the Gaia DR1 positions. Hopefully, this will do for the
object for a few more decades ...
=====
NGC 607 is a double star. (Is it possibly triple? The northern of two images
on the POSS1 looks elongated, as if it were a close double. The DSS image,
from the UK Schmidt, looks like a single star). D'Arrest's position is exact,
and his description appropriate, particularly regarding the 9th magnitude star
29.7 seconds east and 2 arcmin north.
=====
NGC 608. See NGC 618 and NGC 627.
=====
NGC 610 and 611. This pair of objects is probably irretrieveably lost, thanks
to Muller's poor discovery positions. I searched the sky for several degrees
in all directions from the nominal positions, but turned up nothing that
matches Muller's description. In particular, there are no galaxies in the
area with a 10th magnitude star at position angle = 280 degrees, distance 2.4
arcmin. Muller also gives an "accurate" offset of N611 from N610: "Following
previous at PA 60 degrees, dist = 0.5 arcmin," but then adds, "vF *?" This
would be a striking configuration -- even if the second object is a star --
but it's nowhere in the area that I can see. There is no sketch, but even if
there were, it could only confirm Muller's clear descriptions.
Wolfgang Steinicke again drew my attention to this missing pair in July 1998.
I made a further search at "reasonable" digit errors (e.g. 1hr in RA, 10deg
in Dec), but found nothing matching Muller's description anywhere near any of
the resulting positions. It may be worthwhile for other interested
investigators to cover the areas, too -- they may have more luck than I.
=====
NGC 611. See NGC 610.
=====
NGC 614 is perhaps NGC 627, which see. It may also be NGC 618. See that,
too.
=====
NGC 616 is a double star. As with NGC 607, d'A's position is very good, and
his description fits the object. In addition, his offsets -- 14.2 seconds
west and 4 arcmin north -- to an 8th magnitude star are correct.
=====
NGC 618 may be NGC 614 (which is also NGC 627, which see) -- or it may be NGC
608. JH's position points at nothing, and there is no star 2 min 51 sec east
of that position as his description claims. NGC 614 fits his description
("pB, pL, bM") but the fairly bright star follows by only 55 sec. Is there
perhaps a combination of transcription errors and/or typos in JH's offset to
the star? I'm thinking perhaps that the superscript "m" on the 2 in his
description stands for "magnitude" rather than "minute." The star, of
course, is not 2nd magnitude -- this is where the error would have to occur.
Whatever the case, there is certainly an error in JH's position for the
galaxy.
Is his object NGC 608? This is not quite as likely; N608 is the fainter of
the two galaxies in the area. Also, N618 was found during a different sweep
(102) than NGC 608 and NGC 614 (both sweep 106), and different again from N627
(sweep 100), the other "missing" object in the area. I'm tempted to simply
equate N618 with N608, and N627 with N614. But the relative magnitudes, and
the fact that N618 and N627 were found during different sweeps argues in favor
of JH having seen only the brightest object during each sweep.
So, I note the possibility of the identity of N618 with N614 or with N608, but
would not bet my Pentium on it!
-----
Wolfgang has recently (July 2014) looked at the field with JH's observing log
in hand. He suggests instead that NGC 618 is an asterism centered on a bright
star at 01 41 36.8, +33 17 42 (J2000), but I see only a bright (V = 10.1) star
at this position, unlikely to have been mistaken as nebulous. While I've
added this object to the table, I've also added question marks.
-----
Working on a general cleanup of the position file in July 2016, I once again
ran across this object. This time I checked the sweep and found a peculiar
record for this object, number 25 in sweep 102 on 16 November 1827. JH has it
at "-342 beats" and "18' S[outh] of St[ar]." Given that the star is
TYC 2298-44-1 = GSC 02298-00044 = 2MASS J01391229+3341346, this leads to the
position that JH published in his 1833 list and was carried on into the NGC
half a century later.
The "-342 beats" translates into -2minutes 51seconds (2 chronometer beats a
second). It occured to me that perhaps the signs might be wrong. Checking at
the suggested offsets, however, showed no nebulae. Did JH refer his nebula to
a different star, perhaps the double star (WDS J01526+3127AB) that followed
the nebula in the sweep? Again, checking the four possible offsets, I found
no nebulae.
What about the objects that I've suggested as possible identifications? Do
either of these have a star at the correct offset? The answer is "No." This
makes neither NGC 608 nor NGC 614 a reasonable choice. What about Wolfgang's
asterism? Again, there is no star at JH's offsets.
Or NGC 618 could just be a comet. But a search using JPL's "Small Body
Identification" tool, limited roughly to JH's sweep limits in declination and
between RAs of 1hr and 2hrs on his observing date turned up no comets.
So, given that there is nothing on the sky in the area that matches JH's
description and offsets, I have to throw up my hands once again and say,
"Another lost NGC object!"
However, JH adds an interesting footnote at the end of the sweep that may go
some ways toward explaining the situation: "This sweep made with Sir Rufane
Donkin who arrived unexpectedly just as I had begun & staid [sic] the night."
JH goes on to comment on their observations of the Orion Nebula and Rigel
("... which is really superb"), and on the bad weather earlier in the day ("It
had rained hard all day"). Is it possible, I wonder, that the presence of a
distinguished lieutenant general, knighted for service all over the world to
his king and country, and twenty years older than JH, could have perhaps
rattled the younger man a bit? If so, then an extended search for JH's
object, with its offset star, along the belt of sweep might be of some value.
=====
NGC 627 may be NGC 614 (which may also be NGC 618, which see). JH's
description reads "vF, R; another precedes which must be III. 174. The RA
conjectural, and PD liable to some error." As noted in the discussion of NGC
618, JH has three sweeps over this area. During the first sweep (100), he
picked up the two objects noted in his description that I've just given,
during the second sweep (102) he found just one object (N618, which see), and
during the third (106), he found another (N614).
Since there are just two galaxies here, it is reasonable to suppose that JH
picked them both up once, and noticed only the brightest on the other two
sweeps. But, as I noted above, JH's positions and descriptions do not rule
out other interpretations, so this is simply conjecture.
As with NGC 618 (which see), Wolfgang's reanalysis suggests to him that NGC
627 is simply an asterism, this time at 01 42 37.0, +33 34 44 (J2000). As
with NGC 618, I can't make a convincing asterism of the three stars there,
which are about an arcminute apart. Perhaps just the two southeastern stars
of the three might present a nebulous appearance.
So, I am still puzzled by this object. I've added question marks to my old
identifications, and have added Wolfgang's asterism, also with question marks.
=====
NGC 629 is a short line of five stars six or seven arcminutes west-southwest
of Struve's position. I've pulled the data for this from Auwers's list of
novae attached to his catalogue of WH's nebulae and clusters. There he notes
"Not seen in the Heliometer." However, Struve's description ("Irregular
nebula with 3 stars") with his 9-inch Fraunhofer refractor certainly fits the
asterism well enough. It reminds me of NGC 7150 (which see), another --
though somewhat smaller and fainter -- asterism also found with a refractor
(the 15-inch at Harvard) by an experienced observer (G.P. Bond).
I note that Brent Archinal sticks rigorously to Struve's "3 stars", choosing
only the three north-eastern stars. My feeling is that the other two stars
are also part of Struve's object.
=====
NGC 635 is probably MCG -04-05-002 just 3 degrees south of Leavenworth's
nominal position. His sketch matches the galaxy and surrounding star field
very well, so I'm willing to accept that he made a simple mistake in recording
the declination.
=====
NGC 643. This is a star cluster in the SMC. The RC3 incorrectly calls a
galaxy by this name. That galaxy is the one that de Vaucouleurs called "NGC
643B".
"NGC 643A", by the way, is another SMC star cluster, while "NGC 643C" is a
spiral galaxy seen edge on. None of these are related to NGC 643 except by
the near coincidences of their locations on the sky.
=====
NGC 648 = IC 146, which see.
=====
NGC 650 and NGC 651 together form M 76. They are the two bright lobes of a
bipolar planetary nebula. (The fainter, whispy loops to the northwest and
southeast were most likely not seen well until M 76 was photographed.) For GC
and NGC, JH and Dreyer took the lobes as two separate nebulae, put the Messier
number on N650, and the WH number (I 193) on N651.
There is a little justification for this, but not very much. WH was the first
to recognize that the nebula was apparently double. He says of it "Two close
together. Both vB. dist. 2' sp nf. One is 76 of the Conn[oissance des
Temps]." That, strictly speaking, is incorrect as neither Mechain nor Messier
reported the nebula as double.
Still, two NGC numbers it is for the single Messier number. This has happened
at least once more. See NGC 5194 and NGC 5195, the two galaxies comprising
M 51 -- though for that, Messier did see the two separate objects.
=====
NGC 651. See NGC 650.
=====
NGC 652 has a +13 second error in its RA. It shares this with three other
nebulae which Swift discovered the same night. See those (NGC 1450, N1509 =
IC 2026, and N1594 = I2075) for more. Also see N1677 = N1659 for other notes
about that night of 22 October 1886.
=====
NGC 657 looks like a poor cluster of relatively bright stars against the
crowded backdrop of the Milky Way. JH has it as "A ** (h2070), the chief of
a p rich loose cl; sts 12." His position is for the double, HD 10495 =
SAO 22555, but the apparent center -- a rough circle of 5 stars -- of the
cluster is about 4 arcmin southwest of the double.
-----
Brent Archinal makes the cluster somewhat larger and places the center about
2.5 arcminutes west of JH's double. Looking at it again (April 2017), I see a
scattering of about 20 stars centered somewhat north of the circlet of stars I
fingered years ago. Kharchenko et al (2013A&A...558A..53K) in their recent
survey of Galactic open clusters have 18 members within 3 arcminutes of a
center within the circlet, and add another 20 stars when the radius is
expanded to 5.7 arcminutes.
=====
NGC 660 is a nearby, large, distorted galaxy with twisted arms, and dust lanes
and patches, perhaps the result of a recent merger. The nucleus is hidden in
the optical bulge, but is fairly clear in the infrared. I've taken the IR
position from the 2MASS PSC to represent the galaxy, but also include a few of
the optical and radio positions as well.
=====
NGC 674 = NGC 697. The right ascensions are just 2 minutes different, so it
seems likely that N674 is another observation of N697. This strikes me as the
only reasonable interpretation of d'A's observations, in spite of the fact
that he claims to have found N674 on a night when he also observed N697. Is
the night number, 4, perhaps in error? d'A also observed N697 on nights 5 and
93, but saw N674 only once. In any case, the descriptions are virtually
identical, down to the 14th magnitude star 8 or 9 seconds east, and there are
no other objects in the area that d'A would have described as "pB, vmE."
-----
Here's an example of one of my old notes that didn't make a lot of sense until
I pulled d'A's monograph off the shelf. He has just one observation of NGC
674 on his night 4 -- 2 December 1861 -- while NGC 697 = H III 179 has three
observations on nights 4, 5 (3 December 1861), and 93 (19 February 1863). His
description for NGC 674 is (translated from the Latin with the help of Google
Translate):
Quite bright, elongated; GC 398. * 14 mag follows about 7.8 sec in the
parallel.
For NGC 697, he writes:
Night Description
4 Bright, round, brighter in the middle. * 13-14 mag follows 9 sec.
5 Pretty large, bright, oblong, diam = 45", *14 mag follows 9.4 sec;
another 17 mag 11.5 sec a little to the south.
93 Quite bright, pretty large, 50" long; diffuse around the edges.
The brighter of the stars that d'A mentions is 8.5 seconds following the
galaxy -- very close to the average of his estimates -- and the fainter is
11.8 seconds following and 1.15 arcminutes south.
With all that in mind, my earlier comments make more sense. Given that there
is nothing like this at his position for NGC 674, the identity is virtually
certain. Here, then, is a case of two observations on the same night of the
same galaxy -- unless there is a transcription or typographical error
involved. We'll need to go into d'A's log books and records to answer that
question.
WH's observation, by the way, makes the RA 22 seconds too large, but his
description "vF, pL, lE" is appropriate for the galaxy.
=====
NGC 676, a 13th magnitude edgewise S0, has a bright star superposed just a few
arcseconds south of the nucleus. Its visual appearance is well-described in
the NGC.
Its magnitude in CGCG, 10.5, is misleading, of course, applying more to the
star than the galaxy. The galaxy's total magnitude is around 12.5, but has
not yet been measured accurately.
=====
NGC 677 is probably also IC 152, which see.
=====
NGC 684 = IC 165, which see.
=====
NGC 687 is not IC 1737, which see.
=====
NGC 690 is not IC 1741, which see. Leavenworth's sketch points us at the
correct galaxy with two field stars to the northeast in their correct relative
positions and brightnesses.
=====
NGC 696. See NGC 729.
=====
NGC 697 = NGC 674, which see.
=====
NGC 698. See NGC 729.
=====
NGC 700 is CGCG 522-030, not the larger but fainter CGCG 522-027. LdR has
the object 8 arcmin southwest of the center of the NGC 705 group; CGCG 522-030
is 8.1 arcmin southwest, while -027 is 6.5 arcmin west-southwest. Since its
surface brightness is higher than -027's, it is the more likely to have been
seen.
This is indeed Steve Gottlieb's experience. He notes that while he could pick
out -027 in his 17.5-inch reflector, only the nucleus was visible as a nearly
stellar object, while -030 was clearly the more nebulous of the two.
=====
NGC 702 = Arp 75. When I looked at this in 1996, I interpreted it as a triple
interacting object. It still, in fact, looks like a triple on the blue-
sensitive plates. However, on red plates, the faintest of the three objects
looks like a distorted arm of the brightest. On infrared images (e.g. 2MASS),
the third object disappears altogether while the brightest object splits into
two, or has two nuclei. For the current release (October 2013), I've adopted
the interpretation of two galaxies, with the brightest being a single galaxy
with a dark lane across the nuclear region.
-----
Finally looking at the SDSS image in April 2017, I found that this is in fact
an interacting galaxy. The second, nearly stellar, component is superposed
just northeast of the nucleus, and appears to have a plume stretching on
almost straight north. The other "components" that I picked up earlier are
knots in the big galaxy. I've revised the position table to reflect this
revised -- hopefully, somewhat more correct -- interpretation.
Interestingly, the SDSS does not have the superposed companion as a separate
object, while 2MASS PSC, UCAC4, and Gaia DR1 do. This is just another little
reminder that these automated surveys have to be used carefully.
There are also two other fainter galaxies in the field, either or both of
which may be a physical companion. The Arp Atlas shows extremely faint,
distorted, outer arms stretching in the direction of the fainter galaxy to the
east. But that may be a coincidence of optical alignment. Unfortunately,
neither this galaxy, nor the other companion west-northwest of NGC 702 have
published redshifts, so their relationship with the big galaxy cannot be
reliably established at the moment.
=====
NGC 704. This is a double galaxy, a fact actually noted by LdR, but which
Dreyer did not transfer into the NGC. Steve Gottlieb discovered this recently
(March 2014), and suggests that this is another case where positions for both
objects, using the notations "NGC 704A" and "NGC 704B", would be appropriate.
I'll ponder this ...
=====
NGC 705. See NGC 700.
=====
NGC 708 is the brightest galaxy in a group. See the "notngc" files where
Dreyer did not include a fifth galaxy -- 'LdR "B"' -- in the NGC in spite of
having seen it himself.
=====
NGC 716 = IC 1743. Swift's RA for the NGC object is good, but his declination
is almost exactly 40 arcmin too far south. His description -- including the
bright star near east -- is appropriate, so the identity (first suggested
by Dreyer in the IC2 notes) is almost certain.
There is no question of the identity of IC 1743. It was found by Bigourdan,
and his four micrometric offsets point exactly at the galaxy.
=====
NGC 718 is probably not also NGC 728, which see.
=====
NGC 719 = IC 1744. D'Arrest's RA is 13 seconds of time off. This is close
enough that either Dreyer or Javelle might have had some questions about the
identity, especially given that the descriptions are so close. Well, that
didn't happen, so the galaxy has two numbers now.
=====
NGC 723 = NGC 724. JH missed this one when he was putting his GC together.
In his 1833 PT catalogue he notes for h167 (N724): "It is barely possible
[those two words in JH's italics] that this may be III.460 [N723] with a
mistake in reading the PD." When he swept this up at the Cape a few years
later, he specifically noted "No other neb within 15' all around." When he
published his Cape Observations, he added in parentheses, "(N.B. This remark
shows that the nebula No. 167 of my former Catalogue is really identical (as
there suspected) with III.460.)"
Nevertheless, his two objects are entered separately in GC without a note, so
it was left to Dreyer to add a query in the NGC description: "[? = h166]".
JH and Dreyer were both right -- the two numbers do indeed refer to the same
galaxy. RNGC, ESO, and SGC all carried along the equality.
=====
NGC 727 = NGC 729, which see.
=====
NGC 728 is probably the triple star about 1.5 arcmin north-northwest of JH's
position. JH has only one observation of this object which he describes as
"A suspected nebula." D'Arrest could not find this object, though he only
looked for it once. On a night of relatively poor seeing, the three stars
(with a maximum separation of about 20 arcsec) might appear nebulous.
A glance at the Sky Survey suggests that N728 might be a reobservation of NGC
718, about 2 minutes west of JH's place (the declinations are the same to
within the errors). However, JH first observed N718 in the same sweep (No.
95) in which he found N728. So, the two are unlikely to be the same.
=====
NGC 729 = NGC 727. JH describes N729 = h2446 as "eeeF, S, R. RA only rudely
taken by a star, being out of the field." He recorded it only once in Sweep
803.
Much earlier, however, in Sweep 486, he found another nebula in the area, N727
= h 2445. His description of that reads "F, S, R, bM, 15 arcsec." He then
adds (in italics enclosed by square brackets, flagging a note added during the
preparation of the Cape Observations for publication), "It is barely possible
that this and the next nebula [h2446 = N729] may be identical with Nos. 2440
[= N696] and 2441 [= N698] by a mistaken degree in PD." The relative
positions -- the later object in each pair is northeast of the earlier -- as
well as the descriptions [N696: "F, S, R, 15 arcsec;" N698: "vvF, S"]
support the idea. I suspect that JH also had his note about the "rudely
taken" RA in mind when he added his comment several years later.
However, the N696/8 pair was found in Sweep 802, and its RA is 4 min 15 sec
off the N727/9 pair. This means 1 degree errors in both coordinates, rather
than just in Dec as JH points out. Since the position of N729, "rudely
taken" as it is, is close to that of N727, and since the two were seen on
different nights, it seems more plausible to me that the observations refer to
the same object. We can't dismiss JH's comment out of hand, though having
both coordinates off by a degree would be unusual in his southern data.
ESO's suggestion that N729 is a double star at 01 52 01, -36 03.0 (it is ESO
354-**011) seems less probable to me. JH made many hurried observations of
"new" nebulae which have turned out to be identical to objects that he has
securely observed during other sweeps.
=====
NGC 730 is a star. Based on his observations, I suggested earlier that it
might be two of three stars in a line. However looking at the field again in
April 2017, I believe that the northwestern two stars are much too faint for
Bigourdan to have seen with his 30-cm refractor. Here is the remainder of
what I wrote then:
Bigourdan has observations of this on three nights. The discovery
observation on 7 Nov 1885, is only an estimate: +11 seconds and -4 arcmin
from BD +4 328 [I mistakenly called this "BD +5 328" earlier]; there is
nothing at that position, though three stars in a line are south and west.
On 4 Dec of the same year, he has a single micrometric measurement that
falls between the two eastern stars, though slightly closer to the eastern
most. Finally, on 30 Nov 1891, his two measurements point exactly at this
eastern most -- and brightest -- star of the three.
... Bigourdan described the object on the three different nights as 1)
having a "Doubtful aspect," 2) being "Strongly stellar; could be a star 13.4
accompanied by nebulosity," and 3) as "Pretty strongly stellar. Could be a
small nebula or a nebulous star; however, I'm not certain that there is any
nebulosity there." Since even he sounds pretty convinced that his object is
stellar, I'm not about to disagree!
... especially since there are no nebulae in the field.
=====
NGC 731 = NGC 757, which see.
=====
NGC 733 is almost certainly a star. Lord Rosse's observer, Bindon Stoney,
found a group of five nebulae in the area of NGC 736 (the brightest) on 11
October 1850. His sketch is reasonably accurate, though it is distorted in
that it exaggerates the north-south separations between the objects. His
micrometric offsets from N736 also point quite accurately to the surrounding
objects, including the star which I've taken as N733. The sketch confirms the
relative distances in the table between N733, N736, and N740 (the distance
between N733 and N736 is about half that between N736 and N740).
However, at the same position angle as the star, and just 100 arcsec further
from the star which I take as N733, is a faint galaxy. Not otherwise
catalogued, is this possibly the object which Stoney meant to measure and
sketch? Since the evidence from the sketch and the measurements point
directly at the star, though, I'm currently retaining it, and not the galaxy,
as N733. But I've nevertheless listed the galaxy, too, with the requisite
question marks.
=====
NGC 734. This is another of the Leander McCormick objects with a poor
position. It is usually taken as PGC 07121 = 2MASX J01545728-1704477, and is
more or less confirmed by the star about 4 arcmin to the west-northwest shown
on Leavenworth's sketch. However, a brighter star about three minutes to the
south-southeast is not on the sketch. How did Leavenworth miss the brighter
of the two neighboring stars?
Steve Gottlieb has suggested that the galaxy that Leavenworth swept up is
actually 2MASX J01532872-1659442, a brighter spiral with just one star almost
exactly west, where Leavenworth sketched it. Because this galaxy agrees with
Leavenworth's observation much better than PGC 07121, it is the one that we've
adopted as NGC 734.
=====
NGC 736 is the brightest of a group of five. See NGC 733 and NGC 737 for
more.
=====
NGC 737 is a line of three stars in the corona of NGC 736. This object was
variously seen as a single star and as a nebula by the early observers. Lord
Rosse seems to be the first to list it as possibly nebulous, so Dreyer
included it in the NGC. Reinmuth found only the three stars at the place of
LdR's nebula (shown in LdR's sketch of the group around N736, and measured
micrometrically by him in October 1850), and that is all that I see there on
the POSS and DSS, too.
=====
NGC 739. Ralph Copeland found this object near NGC 750 and N751 on 9 January
1874 using Lord Rosse's 72-inch telescope. He measured the distance and
position angle from NGC 750; these point exactly at the galaxy he saw. His
measures of three stars around N739 are also exact, giving further
confirmation to the identification.
In his description of the object, however, he mistakenly has N739
"south-preceding" N750, rather than "north-preceding." When Dreyer
reduced a position for the object during preparation of Lord Rosse's
observations for publication in 1880, he too made a mistake, placing the
position of N739 too far south by 2 arcmin. Thus, the identity with the
galaxy has been missed by most of the modern catalogues.
=====
NGC 740. See NGC 733.
=====
NGC 741 = IC 1751. This, along with NGC 742, was discovered by William
Herschel, reobserved by John Herschel, and by Lord Rosse. N741 itself is the
brightest in a group of galaxies, and the positions in NGC from the Herschels
are good. Furthermore, their descriptions make it clear that all saw the same
two galaxies. They did not pick up any of the other objects in the area.
This leads to the puzzle of why the brighter of the two was also included in
IC. True, it reappeared in Swift's 11th list of "new" nebulae (with one of
his typically inaccurate positions), and was reobserved by Herbert Howe at
Chamberlin Observatory in Denver. Howe provided a very good micrometric
position for it which was adopted by Dreyer for the IC. I suspect that as
Dreyer had come to trust Howe's positions and identifications (most of Howe's
observations are of known objects), he (Dreyer) didn't bother to check the NGC
to see if the galaxy had been seen previously.
More recently, the IC number has been attached in CGCG (and in other
subsequent lists) to the galaxy (CGCG 413-006) just over an arcminute
northwest of N741. This object is indeed brighter than many that Swift found,
but his description of a 9th magnitude star "north-preceding" rather than
simply "preceding" pretty well establishes the identity. It is further
pinned down by Howe's measurement of the distance and direction to the star
(actually a double, or perhaps a single star superposed on a galaxy) which
points exactly to N741 as the object that he measured.
=====
NGC 742. See NGC 741 = IC 1751.
=====
NGC 746. There is no problem with the identification of this relatively
nearby (11-12 Mpc, a bit closer than the Virgo Cluster), low surface
brightness, "semi-dwarf" galaxy (it has about the same absolute magnitude as
the LMC, roughly V_T = -18). It was found on 12 September 1885 by Lewis Swift
with the 16-inch refractor at the Warner Observatory in Rochester, NY. His
description "vF, pS, lE; several sts nr" is also appropriate.
The structure is completely irregular and very patchy; there is not even a
well-defined bar as is common in these late-type irregular galaxies. A quick
scan of the literature via NED in April 2017 suggests that the galaxy has
appeared only in surveys -- I don't find any obvious detailed studies of the
object.
The position is a bit problematic. All the DSS2 images show two bright knots
toward the middle, the brightest being south of the apparent center of the
outer isophotes. The 2MASS PSC picks up these knots easily, while the 2MASS
XSC, the several GSC lists, the Carlsberg Meridian catalog, the USNO-B1.0 --
all blend them into a single object. The galaxy is unfortunately outside the
footprint of the SDSS, so there are no high-resolution images available.
Brian took the position from the GSCA; this is close to the mean position of
the two bright knots, and is finally the selected position that I have kept in
the big table.
A final intriguing possibility is that this is a colliding pair. The red and
IR DSS2 images can be pretty easily seen that way. However, there are none
of the extended streamers around the galaxy that a gravitational encounter
would generate, so I think this is unlikely. The blue image is also most
easily interpreted as that of a typical irregular galaxy without an obvious
bar.
=====
NGC 749 is not IC 1740, which see.
=====
NGC 750 is the western of a well-known pair of interacting ellipticals (NGC
751 is the other). See NGC 739 for more.
=====
NGC 751 is the eastern galaxy in an interacting double (NGC 750 is the other).
See NGC 739.
=====
NGC 755 = NGC 763, which see.
=====
NGC 757 = NGC 731. Both N757 and N763 (which see) were found by Ormond Stone
with the Leander McCormick 26-inch, presumeably on the same night, though he
doesn't give us the dates in the discovery paper. He has, however, left us a
sketch of N763 labeled "Drawn Jany 11.0 1886, sketched Jany 4.5 1885" where
the "1885" pretty clearly should be 1886 (there are a couple of other
sketches from early 1886 where the dates are given correctly).
In any event, this is the western of two relatively bright galaxies in the
area, found by WH early in 1785 (the other, as I noted, is NGC 763 = NGC 755).
Taking Stone's poor positions into account, the true position difference of
the two galaxies pretty well matches the difference in Stone's positions for
his two nebulae. In addition, his descriptions match the galaxies very well,
particularly his estimated magnitudes and diameters (N757: m = 11.0, D = 0.4
arcmin, gbMN; N763: m = 13.0, D = 1.6 x 0.4 arcmin, PA = 65 deg, gbMN).
Even though WH's relative positions are good (his declinations are about 4
arcmin too far north), JH had trouble with his Slough observation for one of
his father's objects (III 265), and apparently did not see the other (III 266)
until his stay at the Cape. Dreyer suggested in the NGC that both referred to
NGC 755. Earlier, I more or less agreed when I wrote, "I suspect that both
observations refer to the brighter western galaxy, N731," though I chose the
brighter rather than the fainter object. Comparing JH's positions now with
the modern places, I think this is wrong and that JH really did see both
objects.
Peters got things sorted out when he micrometrically remeasured the galaxies'
positions (see his second Copernicus article and his discussion in AN 2365).
Dreyer adopted Peters's good positions for the NGC.
Finally, my identification of both N757 and N763 with NGC 755 in the early
versions of SEGC is wrong.
=====
NGC 758 may also be NGC 111, which see.
=====
NGC 760 is a double star found by Copeland with Lord Rosse's 72-inch. His
offset for it from NGC 761 is accurately measured, and his position for N761
is in turn well-measured from one of Lalande's stars. Thus, the NGC position
is good, and the identification not in doubt.
=====
NGC 761. See NGC 760.
=====
NGC 763 = NGC 755. This is the southeastern of two pretty bright nebulae,
originally found by WH. Fortunately, Stone has left us a sketch of the object
which clearly shows it to be N755. Assuming that he found both nebulae the
same night, the northwestern (N757) is almost certainly identical to NGC
731. See the discussion of NGC 757 for more.
=====
NGC 764 may be the double star at 01 54 38.9, -16 18 22. There are no other
candidates for it nearby, and Stone has left no sketch. His description is
appropriate for the stars ("eF, vS, iR, gbM") but given his poor positions
in the two Leander McCormick lists, its identity as N764 is nothing more than
a guess.
Curiously, the next object in Stone's list (No. 46) is not in the NGC at all.
Its position is given by him as 01 54, -09 26 (1890), and is described as
"m = 14.0, D = 0.2, R, gbMN". I do not see why Dreyer left it out of the NGC.
Other of Stone's objects with similar descriptions are included, so the
omission of this one is puzzling. In any event, there is nothing at all in
the area that can be clearly identified with this list entry, so perhaps
Dreyer had reason to suspect it that he has not told us. Also see my notes
for this in the "notngc" files.
=====
NGC 768. Swift has this in his third list where it is number 8, and in his
fifth list where it is number 18. His full descriptions are virtually
identical:
List 3, number 8: 1885 Dec 2; eF, pS, R; B * 32[seconds] f.
List 5, number 18: 1886 Oct 2; eF, pS, R; B * 30[seconds] f, 1' s.
His positions are 20 seconds of time and 1.3 arcminutes apart (see the table
of positions), but his notes about the star make it clear that he saw the same
galaxy both times. The star is HD 12134 at V = 8.3.
Coincidentally, IC 1761 is less than four arcminutes northeast of Swift's
galaxy. It has sometimes been taken as the second object that Swift saw, but
had that been the case, his offset to the star would have read
"B * 18[seconds] f, 4' s". This makes it clear that he did indeed see the
brighter galaxy twice. By the way, Javelle discovered IC 1761 in 1897, saw it
again in 1903, and used HD 12134 as his micrometric comparison star on both
nights.
=====
NGC 771 = 50 Cassiopeiae is a star. During one sweep, JH said, "I suspect
this star to be nebulous." No one since, including JH himself, has been able
to see the suspected nebulosity. JH wrote in GC, and Dreyer quoted in NGC,
"Retained in the catalogue for future occasional observation. Nothing can be
more difficult than to verify or disprove the nebulosity of a considerable
star under ordinary atmospheric conditions."
A quick look (via SIMBAD) at the astrophysical literature on 50 Cas turned up
no observed spectral peculiarities associated with it -- it is a normal A1 V
main sequence star. Similarly, a look at the POSS1 reveals no trace of even
faint nebulosity around the star. JH may have been misled by a moment of
particularly poor seeing.
=====
NGC 772 is a large spiral, close enough that LdR and Dreyer himself saw the
brightest knot in the northern arm. See that story in the "notngc" file under
the object "N0772 HII".
=====
NGC 783 = IC 1765, which see.
=====
NGC 785 = IC 1766, which see.
=====
NGC 789. See NGC 793.
=====
NGC 793. This is one of the few nebulae found by J.G. Lohse, an English
amateur astronomer, working at the observatory of another amateur, Mr.
Wigglesworth. Unfortunately, the observations never seem to have been
published outside the NGC, so Lohse's approximate position and description as
recorded in the NGC is all the information that we have.
For this particular object, the NGC tells us only, "Very very faint, between
two stars; south-following GC 5210 [NGC 789]." The only object in the area
that fits the description is the faint double star about two arcmin southeast
of Lohse's place. It is quite a faint object (it is not in GSC), so Mr.
Wigglesworth must have had a considerable telescope if Lohse was to have seen
it. Some digging in the literature is clearly called for to find the details
we need to know about the observatory and its instruments. Without that, my
possible identification, while fitting Lohse's description, can only be
tentative.
-----
Since I wrote that many years ago, Wolfgang Steinicke has done the historical
research to find that James Wigglesworth's observatory at Scarborough in
Yorkshire housed a 15.5-inch F15 Cooke refractor. This telescope was
certainly capable of turning out the double star that we think might be
Lohse's object, so I've changed the question mark to a colon.
Lohse, by the way, was born in Germany, though worked for much of his career
in Scotland with Ralph Copeland, as well as in Scarborough with Wigglesworth.
Wolfgang's web pages, and his book "Observing and Cataloguing Nebulae and Star
Clusters" (Cambridge, 2010), have more details for those interested.
=====
NGC 794 = IC 191, which see.
=====
NGC 797. See NGC 801.
=====
NGC 799 and NGC 800. Gary Kronk suggested in an email in August 2016 that
Swift has his directions switched in his descriptions of these two in his
"Catalogue No. 2" in AN 2707. I agree. Swift's relative positions, however,
are correct, though his RAs are 30 seconds of time too large. For the NGC,
Dreyer corrected the descriptions.
Herbert Howe, in his first list of observations of nebulae in MNRAS 58, 356,
1898 corrects the RAs, though does not mention the confused directions.
For the record, Swift's entries in his 2nd list for these two galaxies, should
read (with the 2MSP positions precessed to B1885):
No. Date of [alpha] [delta] Descriptions and remarks
discov. 1885.0 1885.0
16 1885 Oct. 9 01 56 19 -00 39 20 eeF; pS; R; n of 2
17 " " 9 01 56 19 -00 41 10 eeF; S; R; s of 2
=====
NGC 800. See NGC 799.
=====
NGC 801. Four other galaxies (NGC 19, 21, 7831, and 7836; see these and NGC 6
for more discussion) discovered earlier in the evening of 20 September 1885 by
Lewis Swift share a common offset in Swift's positions from the true positions
of +1m 10s in RA and +8m 8s in Dec. If we accept the identity of NGC 801 as
given by most catalogues (it is a large edgewise spiral on the northeast edge
of Abell 262), then Swift's position for this object is about -19 sec and -0.9
arcmin off, more in line with Swift's usual precision (or lack of it). Swift
mentions a "double star close following" which may be the faint double near
the southeast end of the spindle. However, both stars are roughly at 17th
magnitude on the POSS1; could Swift have seen them?
Well, there is no other candidate galaxy near aside from NGC 797, and there
are no doubles anywhere near it. So, while the identity of NGC 801 is
somewhat uncertain, I will stick with it for now.
Incidentally, this galaxy almost got an IC number as well. Searching for NGC
801, Bigourdan rediscovered this object -- it is number 473 in his fifth list
of new nebulae. The first four lists were published in time for them to be
included in the NGC or the IC's. The fifth list was not. Consequently, it
has received almost no attention in the subsequent literature.
=====
NGC 804 = IC 1773, which see.
=====
NGC 810. Stephan's position, given in both MNRAS and AN, is correct, but the
NGC position is 10 seconds west. This must be one of the few transcription
errors that Dreyer made in his catalogues.
The galaxy itself appears to be triple on the blue DSS images: a close
dumbbell is oriented southwest-northeast, and a much fainter companion (or
jet?) is just east of the southwestern component. Stephan noted only one
object here, and the dumbbell is just barely noticeable on POSS1. On the
scans of the POSS2 plates, it looks more like a "polar dust ring" galaxy than
two interacting galaxies. It is clearly a single galaxy in the 2MASS images
-- only a single bright nucleus remains visible. The SDSS has the nucleus
intersected by a thin dust lane. The companion galaxy is also well-seen in
the 2MASS and SDSS images, so this is a double interacting system.
=====
NGC 811. The nominal RA, from a single observation by Leavenworth at Leander
McCormick, is about 50 seconds too far east. This is not as bad as many of
the Leander McCormick nebulae, but is still off enough that I did not recover
this for SEGC. The identity is solidified by the star just an arcminute to
the south -- Leavenworth mentions it in his description.
=====
NGC 812. During my earlier push through the NGC, I had noted a "comp or knot
on [the] distorted [southern] arm" of this galaxy. I gave a 1950 position for
it, measured by offset from the nucleus, of 02 03 45.2, +44 19 47. But now,
in December 2013, I don't see anything there on either red or blue DSS images
that would rate special mention. So, I have simply removed the entry for
"N0812se" that I had there.
-----
However (ahem) during a re-evaluation in April 2017, I looked at the infrared
DSS2 image and found another knot, this one in the middle of an apparent bar.
This knot perhaps represents a southern component hidden in dust in the blue
image. It is also near the geometric center of the outer isophotes of the
galaxy, so several previous positions for NGC 812 fall near it.
Unfortunately, there is no SDSS coverage for this part of the sky, so we do
not have high-resolution images to see what is going on with the galaxy. My
"solution" strikes me as thoroughly ad hoc: make two galaxies here where
there may actually be just one. Thus, there are north and south components in
the position table. The northern component is represented by the brightest
2MASS source, so if you need a single object, this is probably the one to
take.
=====
NGC 814 and 815. These two objects, found by Ormond Stone at Leander
McCormick in 1886, have been misidentified or given up as lost by nearly
everyone who has tried to find them. However, Stone's sketch, made a few days
after their discovery, points to the correct objects a full 4.5 minutes of
time east of the recorded (and published) positions. The star field is
unmistakeable, and the objects match Stone's descriptions.
=====
NGC 815. See NGC 814.
=====
NGC 823 = IC 1782, which see.
=====
NGC 826. This is probably better taken as the interacting pair rather than
just the southern brighter component. Stephan's position, from micrometric
measurements on one night in September 1871, falls roughly midway between the
two galaxies, though we perhaps shouldn't make too much of this as the pair is
quite faint.
In any case, I've changed the position table to reflect my revised
interpretation.
=====
NGC 832 is probably NGC 1226. Earlier, I wrote about this:
NGC 832 may be a double star. D'Arrest has only one observation of the
"nova," noting a star 9-10 about 5 arcmin southwest. There is such a star
about four arcmin southeast of his position (copied correctly into NGC), but
there is nothing at his position nor is there another bright star southwest
of it.
However, about 4 arcmin northeast of the star is a faint double star. It
is 24 seconds east of d'A's position, and just 0.2 arcmin north. It is the
sort of object that he could have seen as a "F, S" nebula on even a good
night. Lacking any other candidate, this is a possible choice for his nova.
In July 2016, putting in nominal positions for doubtful objects, I noticed
that if the RA of d'A's object were to be increased by 1 hour, his position
would fall within 1.5 arcminutes of NGC 1226 which does have a star of the
right magnitude about 4 arcminutes southwest as d'A mentions.
However, there are actually two stars to choose from! So why didn't d'A
mention both? This is my only caveat. I mentioned this in an email to Yann
Pothier; he replied that d'A's fields of view were sixteen arcminutes at 95X
and just 12 arcminutes at 147X. He suggests that the further star was right
on the edge of d'A's field, or just outside of it. This may explain the
"missing" star in d'A's description.
So, I'm going to suggest that d'A made a 1 hour error in his RA for NGC 832,
just as he did with NGC 3167 (= NGC 2789), NGC 3575 (= NGC 3162), and NGC 3760
(= NGC 3301).
I've left the double star in the big table as "NGC 0832?" even though I am now
pretty well convinced that NGC 1226 is the correct object. Just covering all
the possibilities ...
=====
NGC 834. This was discovered by WH, who remained its sole observer at the
time the NGC was compiled. See NGC 841 for more.
=====
NGC 841 is the brightest of three galaxies forming a small group (the others
are NGC 834 and 845). Though credited to Stephan (who has a note that it is
clearly distinct from the other two, indicating that he saw all three), it was
actually found by WH, and observed by d'Arrest.
Interestingly, JH saw only the faintest of the three. Though his position is
virtually exact for it, he was enough convinced that his object and his
father's were the same that he equated them. So, in GC he noted a 1 minute of
time difference in the RA's and adopted his own. For N834, he used his
father's position since he did not come across it during his own sweeps.
Thus, when Stephan observed the trio, he found two GC objects at their correct
positions, and a "new" nebula which he measured and included in his list of
"novae".
Like WH, d'A also saw only the brightest of the three, but made the RA about
13 seconds too large (17 seconds larger than WH's). He, too, assumed that all
the observations referred to the same object, so that is how Dreyer put them
into NGC. There, Dreyer adopted d'A's RA for NGC 845.
The credits for H III 604 and d'A need to be moved from NGC 845 to NGC 841.
Aside from that and the adjustment needed for the RA of N845, the NGC is
pretty close to being correct.
=====
NGC 843 is a triple star very close to d'A's position. He describes the
triple as a faint, small, round globular cluster. On a night of less than
perfect seeing, that is how the triple must appear.
=====
NGC 845. This is the faintest of three galaxies, and the only one seen by JH.
(It was also seen by Stephan, though Esmiol merely calls it "Anonyme"; see UGC
03840 and UGC 4227 in the "notngc" files for more.) For this galaxy, we need
to move the WH number (III 604) and the other observer credit to d'A to NGC
841 (which see). That is the brightest of the three.
=====
NGC 846 = NGC 847. Stephan's micrometrically measured position is very
accurate; Swift's position, estimated from setting circles is not too bad, and
his description of the four field stars nearby is appropriate, too.
The identity, first suggested by Spitaler in the early 1890's and included in
the 1st IC, is certain.
=====
NGC 856 = NGC 859. See NGC 863.
=====
NGC 859 = NGC 856. See NGC 863.
=====
NGC 863 = NGC 866 = NGC 885 and company.
The problem here is what to do with the five observations reported by Lewis
Swift in his fifth "catalogue" of nebulae, published in Astronomische
Nachrichten No. 2763 (Vol. 116, page 33, 1886). All five received NGC
numbers: 856, 859, 866, 868, and 885. So, in addition to NGC 863, found by
William Herschel (H III 260), there are six numbers in the area and but only
three fairly bright galaxies.
NGC 863 itself is no problem. The NGC position, from JH's observations, is
very good (there is a 30 second error in WH's RA; see Dreyer's note in his
edition of WH's Scientific Papers). It obviously pins down the brightest of
the galaxies in the area (which, by the way, is Markarian 590). Another of
the galaxies is very nearly as bright (Mark 590 and this second galaxy are
listed at m_p = 14.0 and 14.4, respectively, in the CGCG), and I'm a bit
surprised that the Herschels did not see it.
These two are obviously the two brightest that Swift found on the night of 3
October 1886 (N859 and N866, numbers 23 and 24, respectively, in his AN list).
The relative positions that he gives them are correct -- "np of 2" and "sf
of 2." The declinations are not too bad, but the RA's are out. The third
object that he found that night is NGC 868; the position is not too bad, and
the description (what there is of it: "eF, pS, R") is appropriate.
Swift returned to the area on 31 October of the same year, finding two more
objects. The first of these, NGC 856 (the 22nd object in Swift's list), has a
good position, and the description ("eF, S, lE, F * close") is again
appropriate. The star was measured by both Bigourdan and Howe, and is about a
minute of arc east and slightly north of the galaxy. The second object,
NGC 885 (number 27), has -- if my conjecture is correct -- the largest
positional error of any of Swift's five objects here: five minutes of time in
RA. Swift's declination is good.
What I believe happened on this night is that Swift simply rediscovered the
two brightest galaxies. So, NGC 859 = NGC 856 and NGC 885 = NGC 863. His
descriptions of the brightnesses of the two objects, though, is systematically
fainter -- "eF" vs. "pF" for the fainter of the two, and "vF" vs. "pF"
for the brighter -- than on his earlier night's observations. This suggests
to me that the sky was not as good on this second night as on the first, or
that Swift was then simply noting nebulae as fainter.
The right ascension problem for NGC 885 is, I believe, one of Swift's large
random errors that are littered throughout his lists. For example, in the
same list, NGC 1689 (found 22 October 1886) is also five minutes out, being =
NGC 1667. Another example: NGC 1037, also in the same list, has as a part of
its description "[GC] 581 in field." This means that GC 581 = NGC 1032 must
be within about 16 arcminutes of Swift's object (Swift was using an eyepiece
that had a field diameter of 33 arcmin), but his declination for NGC 1037 is
2 deg 49.7 arcmin different from NGC 1032's declination!
In summary, then, I think that my original assignments of the NGC numbers are
probably correct, though we do not have the evidence to be absolutely sure.
The observations reported by Herbert Howe in M.N. 68, 356, 1898, and 69, 29,
1900, support my position: he could not find NGC 859, NGC 866, and NGC 885,
though he reports observing NGC 856, NGC 863, and NGC 868. Bigourdan also has
observations of only three objects here, though he assigns a different number
to the faintest: NGC 859 rather than NGC 868. I've yet to sort out his data
completely, however.
=====
NGC 866 = NGC 863 (which see) = NGC 885.
=====
NGC 867 may be the same galaxy as NGC 875. Or it may be the same as IC 225.
Or it may be neither, or another galaxy altogether. I don't have enough
information to tell. Here is the story.
This is the second of WH's third class (very faint) of nebulae, found during
his first season of sweeping the sky. He placed it "13 minutes :: following,
-- north" of 60 Ceti. Dreyer has a note in the Scientific Papers that reads
(in full):
Sweep 61, Dec 21, 1783. "An almost invisible F. neb., it is R. and about 8
or 10 arcsec diameter, being brighter in the center than outwards. It can
only be seen when the glass is perfectly clean and the attention confined to
the object." By two diagrams, it is about 1 1/2 deg nf a star which was
taken to be 69 Ceti, but obs. was interrupted by clouds. Not found by
Bigourdan twice.
In his 1912 MN list of corrections to WH's NGC nebulae, Dreyer shortens this
to read merely, "The place of III.2 is extremely uncertain."
The suggestion that it might be NGC 875 comes from d'A who found N875 and
measured a pretty accurate position for it. Dreyer copied this suggestion
into the NGC description for N875. Auwers, in his reduction of WH's nebulae
places N867 at "02 07 29, -1::" for 1830 which places it at 02 13 37, -0.5 for
1950. This is more than a degree south of the GC (and NGC) position, and I
wonder if Auwers has his declination sign wrong. He has no note for the
object, nor does JH in GC.
And that is pretty much it as far as the observations go. The crude offset
from 60 Ceti suggests that N875 is the galaxy WH saw, while the 69 Ceti note
suggests that IC 225 might be his object. NGC 875 is brighter by half a
magnitude and is therefore the more obvious choice, but the agreement of the
diagrams -- assuming the identification of the star as 69 Ceti is correct --
is also compelling.
We will have to go back to WH's observing records for the sweep to look for
other clues. For example, I suspect that Dreyer has replaced the original
offset published in PT, but that is only a suspicion, based on JH's adoption
of a fully-reduced position in GC, and on Auwers's partially-reduced position.
So, at the moment, all I can say is "NGC 867 may be the same galaxy as NGC
875. Or it may be the same as IC 225. Or ..."
-----
I find Dreyer's note in the Scientific Papers a bit curious. CH's fair copy
of the Sweep says only "A nebula eF, R, 8 or 10[arcsec] d, bM. 60 Ceti f
13[min] PD about 89[deg] 53[arcmin]. For description see F[ixt] St[ars],
Vol. 5, page 476". Dreyer apparently copied that description into his note.
The curiosity comes because CH has clearly written "60 [sixty] Ceti", not
69 [sixty nine] Ceti". Though that star, whichever one it is, is the only
star in the sweep, it's clock correction agrees reasonably well with the only
other star with a similar correction from the same night, 55 Piscium in the
previous sweep: -5h 37m 02.9s for 60 Ceti, and -5h 29m 39.8s for 55 Piscium.
Had the star been 69 Ceti, the correction would have been -5h 18m 17.7s. The
difference of nearly 20 minutes with 55 Psc compared with just 7.4 minutes
makes the identity of 60 Ceti more likely in my mind, though the other is
certainly possible.
So, I come back again to NGC 875. That fits WH's description, and while I am
not going to change the question mark on the identification, I think the
meager evidence leads us to this galaxy as WH's object from his early sweep.
The position I give in the table, by the way, is CH's 1800 position (02 05 37,
89 58 [NPD]) precessed to J2000. It is clearly very uncertain with the RA
given to a full minute of time, and the NPD merely estimated.
=====
NGC 868. Until I saw the SDSS image early in May 2017, I could not be sure
that the superposed star was not actually a companion galaxy. The SDSS
clearly shows it as a star, so the previous versions of the position table got
the type wrong.
Also see NGC 863 where this figures in the identification of several of Lewis
Swift's nebulae.
=====
NGC 869 is the western partner of the famous "Double Cluster". See NGC 884
for a bit more on these spectacularly fine naked-eye objects.
=====
NGC 872 is one of the few Leander McCormick nebulae that is absolutely,
positively identified. Not only did Leavenworth observe it three times, he
made two sketches of the field. Even so, the nominal RA is 46 seconds of time
off the true RA, an indication of the poor quality of the early LM positions.
See NGC 412 for an LM nebula, found and sketched the same night as one of
N872's, not so fortunate in its observation.
By the way, I identified this galaxy as NGC "842" in previous releases of this
notes file. I did that consistently throughout the file, not just as an
isolated typo, clearly the result of a brain freeze. I'm grateful to Steve
Gottlieb, who caught this, for letting me know with polite good humor.
=====
NGC 874. Though Muller's position is off, his description is exact,
including the position angle of the galaxy and the position angle and distance
of the neighboring star. The RC3 is correct in this case.
-----
In July 2016, John Ponting sent an email noting that my earlier comment is not
correct in its reference to the neighboring star (star "A" in what follows).
Here is what appeared in the second Leander McCormick list with respect to
this galaxy:
No. RA (1890) Dec m D x d "Form" n Obs Notes
329 02 11.1 -23 42 15.5 0.3x0.1 E 170[deg] 1 M **?; *10, P320[deg]
[delta] 2.8[arcmin]
The star's position angle is actually close to 27 degrees rather than the 320
degrees that Frank Muller recorded, though the distance is correct.
John notes another star (star "B") of very similar magnitude at PA = 320
degrees and distance = 5.1 arcminutes. Given this, he has suggested four ways
in which Muller may have confused his observation:
"(1) Muller was referring to 'A', got the distance right, but measured the
angle completely wrong (67[deg] error; most of his angles are within
10[deg])
(2) He was referring to 'B', got the angle spot on, but measured the
distance completely wrong (2.3' error; most of his distances are within
0.5')
(3) He measured both stars and compressed these readings into one, managing
to take bits from each (seems very unlikely to me)
(4) He was referring to 'A', whose angle he measured as 32[deg] (which is
within his normal angle accuracy), but an extra '0' got added in error
when the list was published. (This seems to me to be the most likely.)"
I can add a fifth possibility to this list: Muller recorded his star in the
wrong quadrant, intending "40[deg]" instead of 320.
Whatever happened, the identity of the galaxy is pretty sure. Rather
surprisingly, Muller's RA is close to the real value while his declination is
7 arcminutes too far north. But his description of the galaxy and its nearby
star -- aside from whatever error he made -- are close to what we see on the
sky today.
=====
NGC 875 may also be NGC 867, which see.
=====
NGC 884 is the eastern, larger member of the famous "Double Cluster"; the
western member is of course NGC 869. There are 8-10 very bright stars
scattered over the face of this cluster; most of these are probably M-type red
giants. The clusters are part of a much larger stellar association spanning
at least six degrees, but each cluster is pretty well isolated. They do, of
course, form an actual physical pair at a distance of about 2.2 kpc, and the
total population of both clusters combined probably tops 20,000 stars (see
e.g. Currie et al., ApJS 186, 191, 2010).
Absorption is patchy across the face of this cluster, so its diameter from
visual inspection is probably not well-determined. In particular, the
canonical core of the cluster appears to be in the southwestern part, while
the overall distribution of stars is uneven over an area of 20' x 20' as seen
on the DSS2 red image. The center, near 02 22 20, +57 11.2 (J2000) is well
northeast of the core (02 22 04, +57 07.8) and there appears to be a "hole"
(centered at 02 22 36, +57 07.9) in the distribution of the brighter stars.
=====
NGC 885 = NGC 863 (which see) = NGC 866.
=====
NGC 886. Thanks to a typo ("6" for "5"), this appeared in an earlier
unpublished errata list of mine as being equal to NGC 863. It is not, of
course.
It is actually a scattered cluster of about 20-30 stars centered near JH's
position. It's obvious on the POSS; nevertheless, RNGC chose to call it
"non-existent." See Brent's Monograph on the "non-existent" clusters for
more.
=====
NGC 894 is the northwestern arm of NGC 895. Lord Rosse and his observer at
first thought that this was a double nebula. But their description makes
clear that, after some study, they regarded the two as parts of the same
extended system. This, of course, is just what they are.
=====
NGC 896. Though WH noted the polar distance as uncertain, his position is
only 4 arcmin south of the nebula, a bright knot in a huge HII ring (or
possibly a supernova remnant). In addition, CH has reduced a position with
respect to another star in the sweep (HD 24480) that is almost identical with
that derived from the offsets published in WH's PT paper (the second catalogue
of nebulae and clusters).
Wolfgang suggests that this is identical to IC 1795 (which see), found by
Barnard. I think that is unlikely as Barnard's position is close to another
knot in the same nebula. Unfortunately, Barnard's observation is apparently
one that he communicated directly to Dreyer, so we cannot easily check its
details. Until we can see that observation, I am going to assume that Barnard
(and Dreyer) knew about the proximity of the two objects and thought they were
different enough to warrant two numbers.
=====
NGC 900. See NGC 901.
=====
NGC 901 is just 2.8 arcmin nnf NGC 900, and the NGC position (from Marth, who
found the pair) is very close to the true position. Nevertheless, this has
not prevented MCG and RNGC from getting the identification wrong. MCG calls
N900 "N901," and RNGC claims N901 to be non-existent (though it does get
N900 right). In spite of this, the identifications of the two objects are
clear.
=====
NGC 917. JH's position is exactly 20 arcmin too far north in declination.
His description, "vF, S, R; forms a semicircle with four stars" from a
single observation in Sweep 106 is a prefect match for UGC 1890 and four
nearby field stars.
Lord Rosse looked at the area of JH's published position, but saw only several
very faint stars. There are two double stars about an arcminute south of JH's
place. These are very faint; while they might have been visible in the
72-inch, it's very unlikely that JH could have seen them with the 20-foot
reflector.
In any case, UGC 1890 is almost certainly the object he saw. The galaxy and
the nearby stars match his description exactly.
-----
Entering the Archinal and Hynes positions for the Galactic clusters in May
2016, I was surprised to run across NGC 917. It is listed in AH as an
asterism at near JH's uncorrected position with a diameter of one arcminute.
Here is what Brent has to say about it:
Forms semicircle with 2 stars NW and 2 stars NE as J.H. indicated. Triple
and double stars on E and W sides. Alias: h 220.
I see what Brent is talking about, the two double stars south of JH's
uncorrected position. As I noted above, however, these stars are very faint,
and I doubt that JH could have seen them.
I checked the sweep (No. 106 on 22 Nov 1827) where it is number 32 -- JH gives
some additional information that did not make it into his 1833 catalogue. In
particular, there is a diagram showing the stars and nebula:
* 2 S
^
1 * |
E = 15 deg. On the second night, Bigourdan claimed to
see stellar objects at the very limit of visibility where he placed N2529 and
N2531 earlier, but he did not attempt to measure them. It's clear to me that
the two do not exist, probably being those faint illusions that we all see now
and then when we get tired or try too hard to push the limits of our optics.
May 2008. Jeffrey Corder has suggested that the southern arm of NGC 2530
might be NGC 2531. I think this is unlikely for several reasons. First, the
arm's surface brightness is very low. It also does not extend as far to the
south as the star at = 15 deg is to the north, yet Bigourdan estimated
the distances to be equal. Third, on one night, he called NGC 2530 itself
"extremely faint, only suspected," and did not mention any other objects near
it. Fourth, while there is a faint knot at the end of the arm, its position
angle with respect to the galaxy's nucleus is closer to 170 degrees rather
than the 150 that Bigordan estimated. Finally, Bigourdan claimed to have seen
two stellar objects south of the nucleus -- the arm would be only one of these
were it one of Bigourdan's objects.
While I think these are sufficient to cast doubt on Jeff's suggestion, I have
not seen the field with a telescope of the size that Bigourdan used. It is
just possible that he could have seen the galaxy's arm with his long-focus
refractor.
=====
NGC 2530. See NGC 2529.
=====
NGC 2531. See NGC 2529.
=====
NGC 2542 = 19 Puppis = SAO 153942 = ADS 6647. JH may have been misled by the
faint companion to the brighter star. With a separation of only 2 arcsec, and
a magnitude difference of 6.5, it would be very difficult to make out the
fainter star except under extraordinarily fine conditions.
Reading what I wrote "several" years ago in March 2014, I'm struck by its
irrelavance with what JH had to say about the star: "A fine nebulous star 6'
m, in the following part of the cluster [NGC 2539], and almost unconnected
with it. The nebula is faint, but I feel confident that it is not the
nebulous haze. (Notandum. -- Nothing more difficult than to prove a nebulous
star of the 6th m and above.)" While this might be a description of a very
close double star, it just doesn't read like it.
Yet, the conclusion is still the same -- there is no obvious nebulosity around
the star on any of the optical sky surveys. So what did JH see? We can only
take him at his word, and accept the suggestion of faint nebulosity here that
is overwhelmed by the light of the star on photographs. But we still need to
prove that the nebulosity is indeed there.
=====
NGC 2543 = IC 2232. The galaxy was first seen by WH in Feb 1787, and was
reobserved in Mar 1790. The two positions that he measured are not in
particularly good agreement (08 09.6 +36 20 and 08 09.8 +36 35). JH picked it
up once in Feb 1832. His position is 08 11 45, +36 24.6, also not in good
agreement with either of his father's determinations. However, Sir John notes
a "a coarse ** p points to it." This note is correct, and the "double star" is
quite wide.
The GC and NGC adopted sort of a mean of these three (08 10 43 +36 24.7)
which was corrected by Dreyer in the IC 1 notes, following Spitaler (08 09 38
+36 24.7). Actually, Spitaler's micrometric position (measured in Dec 1891)
reduces to 08 09 42.9 +36 24 07, using the GSC position for his comparison
star, and ignoring its (unknown) proper motion.
Javelle scanned the field in Feb 1896 and his position (for IC 2232) reduces
to (again ignoring proper motion) 08 09 42.5 +36 24 12, agreeing well with
Spitaler. Thus, there is no question that the two different numbers apply to
the same object.
This identity was first suggested as being the same as N2543 by Reinmuth in
1926, and every catalogue since has made the equality. The descriptions of
the galaxy and the surrounding star field simply nail the lid, leaving no
doubt about the equivalence of the two entries.
=====
NGC 2546. JH found this cluster in three sweeps. His first position is
representative of the entire cluster, very close to a position plucked from
the DSS2R image. His other two positions point at the northeastern end of the
cluster.
Unfortunately, ESO put this number on a much larger, scattered group of stars,
and made the position 45 seconds of time further east and 10 arcmin south. If
this is indeed the center of a larger cluster, then NGC 2546 is just a small
part of it.
=====
NGC 2554. There is no problem with the identification of this galaxy, but as
Steve Gottlieb recently (April 2014) pointed out, the faint companion (CGCG
119-032) was seen by LdR, but mistaken for a star. The SDSS photometry for
this object makes it among the fainter galaxies picked up with the 72-inch
(B = 16.53, V = 15.57, and R = 14.94), only half a magnitude brighter than
NGC 2603 (which see).
I also mention the companion in the "notngc" files, where I essentially repeat
this note.
=====
NGC 2571 is a scattered cluster that both Herschels noted as being at least
15 arcmin across if not larger. Brian Skiff made it only 8 arcmin, and the
largest I can go is around 13 arcmin. But the position is good, and there is
no doubting the identification.
=====
NGC 2574. See NGC 2589.
=====
NGC 2582 = IC 2359. Here is a curious case. This is clearly noted as NGC
2582 in Wolf's first list, yet Dreyer still assigned it an IC number. There
is no particular reason that he should have done this that I can see. The NGC
position (from the two Herschels) agrees well with the GSC position, and with
Wolf's position, and the descriptions are compatible. Oh, well -- these
things happen.
=====
NGC 2583 is a minute west of its nominal position. See NGC 2586 for more.
=====
NGC 2584 is a minute west of its nominal position. See NGC 2586 for more.
=====
NGC 2585 is a minute west of its nominal position. See NGC 2586 for more.
=====
NGC 2586. This is a triple star. The galaxy with this label in RC3 (MCG
-01-22-012) is near the nominal position, but N2586 is noted as the fourth of
four nebulae. The other three (NGC 2583-5) are a minute west of Muller's
position, but their relative positions are good. If N2586's relative position
is similarly good, then there is little doubt that it is the triple star.
=====
NGC 2589 is probably lost. There are no bright galaxies near Swift's
position, though NGC 2574 (4 minutes preceding and 9 arcmin south) is a
possibility. Given Swift's meager description, however -- "pF, pS, lE in
meridian" -- this is little more than a guess.
=====
NGC 2590 = IC 507, which see.
=====
NGC 2597 is a double star. It is the preceding of two close "nebulae" that
Marth found on New Year's night, 1864. The double is near Marth's place, as
is his other object, NGC 2598, a galaxy.
=====
NGC 2598. See NGC 2597.
=====
NGC 2599. See NGC 2600.
=====
NGC 2600, 2602, 2603, 2605, and 2606. There is a group of six galaxies here.
Two (N2602 and N2606) of the three brightest were seen twice by JH, while he
curiously missed the brightest, N2600 (LdR and Bigourdan picked this up). Of
the three others seen by LdR, JH and Dreyer gave new GC and NGC numbers to
only two, the other being taken as a star once, and being thought as one of
the other two "novae" the second time.
[There is also some confusion in LdR's 1861 PT paper, noted by JH in the GC
Notes and by Dreyer in LdR's 1880 monograph, with NGC 2599 (= h507) 30 degrees
south. Both JH and Dreyer come to the correct conclusion that this is a
simple transcription error and that the correct numbers are h508 (= N2602) and
h510 (= N2606).]
JH's observations are relatively clear, though he does note a 10 second RA
discrepancy between his first and second observations of N2602 (the second is
more nearly correct). Also, his note "... np a star (about [PA =] 5 deg np)"
should read "sp" instead of "np". As I've noted, his observations point at
the second and third brightest in the group as being the two that he found.
The first time LdR went over the group, he found three nebulae:
1850, Feb. 9. A fine object, 3 neb., one (N2600) B, another (N2606)
f[ollowing] pB and E, the third (N2602) north and the last degree of
faintness. [Dreyer appends the note about N2599.]
LdR's second observation turned up four nebulae, and he provided a sketch:
1858, Mar. 11. 4 neb. found, alpha (N2603) is F, S, bM; beta (N2605) is
vvF, gamma (N2602) F, S, lbM; delta is E and has a Nucl, a F * sf. alpha
and gamma are about 5 arcmin dist. from one another, and beta and delta
about the same dist. apart.
Interestingly, he includes the faintest galaxy in the group in the sketch, but
has it drawn as a star.
Finally, a third observation yeilded only two nebulae:
1867, Mar. 5. 2 neb. seen nearly pf, p one (the unnumbered faintest galaxy
in the group) eeF, f one (N2606) eF. Measures extremely difficult. Pos. 92
deg (2). Dist. 118 arcsec (1).
In each case, the noted relative brightnesses and positions very clearly
identify the objects that LdR and his observers are seeing. I find it
informative that he turned up a different set of objects each night, pointing
most likely to the importance of seeing, transparency, observer skill and
fatigue, mirror reflectivity, and a host of other variables that determine the
eventual outcome of any given observation.
When Bigourdan went over the field, he found only the brightest three
galaxies, N2600, N2602, and N2606, noting the others as simply "Non vue" (not
seen).
Making sense out of all of this is fairly straight-forward (though I swapped
NGC 2602 and NGC 2605 in my first pass a few years ago; apologies to all). We
simply adopt the NGC numbers for JH's two objects as given by Dreyer. JH's
positions are not bad, either, though both he and Dreyer used a mean of the
two discordant RAs for N2602. NGC 2600 is easy as its relatively good
position comes from Bigourdan, and his comment about the two stars preceding
is accurate.
This leaves NGC 2603 and NGC 2605 to distribute among the three "novae" found
by LdR. I've arbitrarily assigned these to the fourth and fifth brightest
galaxies in the group (LdR's alpha and beta), leaving only the sixth and
faintest without an NGC number. I've included this in the position table as
"N2606 w comp". The final entry in the table, "N2606 e comp" is the "F * sf"
that LdR notes in his 1858 observation. On the DSS, this looks like a close
double, or perhaps another companion galaxy.
=====
NGC 2602. See NGC 2600.
=====
NGC 2603. Is this the faintest NGC galaxy? The SDSS photometry (cModel
magnitudes), transformed to BVR, gives B = 16.96, V = 16.19, and R = 15.59.
I'll look into other very faint ones, too.
See also NGC 2600 for general notes on the field.
=====
NGC 2605. See NGC 2600.
=====
NGC 2606. See NGC 2600.
=====
NGC 2617 is the brighter and western of two galaxies (it is MCG -01-22-026).
The NGC position, from Stephan's careful micrometric measurements, is within a
few arcseconds of being correct, so I'm puzzled by the occasional
misidentification of this NGC number with the eastern galaxy (MCG -01-22-027).
This is especially disconcerting since the eastern galaxy is considerably
fainter as well.
Oh, well.
=====
NGC 2618. Courtney Seligman has pointed out a problem with the RA correction
to the NGC position of this galaxy quoted by Dreyer in the IC1 Notes. Dreyer
writes there, "R.A. is 8h 29m 1s (Bigourdan)." This, however, leads to the
wrong position for the galaxy. Here is the (perhaps overly detailed) story,
taken from an email to Courtney in September 2017. For reference, the J2000
position of NGC 2618 is 08 35 53.5, +00 42 25.
WH discovered this on 20 December 1784, but with no stars in the sweep (Sw
346), he was forced to use a star from the previous sweep for his
comparison. His resultant position is 08 36 36, +00 39.1 (precessed to
J2000). JH published 08 36 01, +00 42.4 (again J2000) but marks both
coordinates with "::" and comments "Extremely doubtful as I could not
recover the object." I checked his observing log for 27 Jan 1832, Sweep 397
and found he has exactly the same comment penciled in place of a
description.
Nevertheless, JH's is the position that Dreyer adopted for the NGC without
any comment about its being pretty uncertain. Dreyer, of course, has a note
in his 1912 Scientific Papers (of WH) that reads "R.A. 48s too great
(Bigourdan). There was no star in Sweep 346, so that H. had to use 13 Canis
from the previous one."
This leads us to Bigourdan's observations and comments. After looking into
it, I am a bit puzzled by his comment in CR 112, 850, 1891: "Found 12s
after the NGC position." Then, he apparently reworked the reduction as he
says in his big table of observations: "This nebula is found 13 seconds
before the NGC position." The galaxy actually precedes the NGC position by
7.5 seconds, and Bigourdan's observations of 15 March 1890 reduce to almost
exactly the modern position for the galaxy. His comparison star is just
where he says it is, 25 seconds west and 11 arcminutes south of BD +01 2137.
I thought that the large proper motion of the star (-118.8 mas/yr in RA and
+28.6 mas/yr in Dec) might have had something to do with the problem, but
even ignoring the RA proper motion leads to a difference in the reduced
position of only about 1 second of time, so that's not it. I checked
Bigourdan's list of errata in his introduction to the full series of
observations, but he has nothing for NGC 2618.
So, it looks to me like WH was 42 seconds off in his RA, JH (and NGC) only
7.5 seconds off, and Bigourdan spot on. So, I just can't see where
Bigourdan's +12 and -13 second comments come from. Even if he used the BD
position for +01 2137 as his starting point, he would have ended up only
about 5 seconds of time off, not the 13 he reports in the big table of
observations.
Also, I can't find anything near his position for Big 151 = IC 518. At
least his comment in the big table "This object is found in the place given
by the NGC for NGC 2618" is consistent with his comment for NGC 2618. But
there is nothing in the area but the NGC galaxy. I suspect this problem
might have a solution if we could see Bigourdan's reductions (if they still
exist). But since we know the final answers -- a single galaxy called "NGC
2618" and nothing at all to hang "IC 518" on -- I'm not inclined to go out
of my way to dig much further.
Also see IC 518 for a bit more on that "object".
=====
NGC 2623. See IC 2386.
=====
NGC 2629. See NGC 2630.
=====
NGC 2630 and NGC 2631. These two objects were found by Tempel (apparently in
1883), and described in his note in AN 2660. Of the twelve novae mentioned in
the note, these are the only two not listed in his table. It is remarkable,
too, that he nevertheless describes them as "much brighter" than NGC 2629
and NGC 2641, both seen and measured by the Herschels and by d'Arrest.
At the moment, my feeling is that Tempel confused NGC 2633 with NGC 2629, and
that his pair is actually NGC 2634 and NGC 2634A. These two galaxies are the
only ones in the group that are close enough to be actually called a "pair."
However, while N2634 is bright enough to rival the earlier observers'
discoveries in the area, N2634A is certainly not. It's just conceiveable,
however, that on a night of exceptional transparency, the pair may have stood
out enough to capture Tempel's attention. He was, in fact, so struck by their
brightness -- compared to the nearby nebulae that the Herschel's and d'Arrest
found -- that he suggested variablility for them.
This is a pretty weak argument, however, so until Tempel's discovery sketch
(which he mentions explicitly) can be examined, the question of the identities
of these two NGC numbers has to remain open. So, I've simply entered the NGC
positions in the table for the time being.
=====
NGC 2631. See NGC 2630.
=====
NGC 2633. See NGC 2630.
=====
NGC 2634. See NGC 2630.
=====
NGC 2637 is one of two galaxies found in the eastern part of the Beehive by
Marth in 1864 (the other is NGC 2643, which see). Both are placed by Marth
too far south by about 10 arcmin, and too far east by 6 and 18 seconds,
respectively. The eight other objects that Marth found that same night show
no such offsets from the true positions, but these two are reasonably
consistent with each other, and are fairly close on the sky. I'll take the
identifications since nothing else in the area matches.
=====
NGC 2641. See NGC 2630.
=====
NGC 2643 = IC 2390. This identity, first suggested by Reinmuth, was taken up
by RNGC. The object was found by Marth in 1864. Correcting his position by
18 seconds of time and 11 arcmin leads to IC 2390. The IC object matches
Marth's description, and there is no other object in the area (the east edge
of the Beehive) that would fit better. NGC 2637 (which see), found by Marth
the same night, also suffers from a declination error of 8 arcmin of the same
sign, though the RA is only off by 6 seconds.
=====
NGC 2646 = IC 511, which see. This galaxy also has a curious history in my
own work with the three Reference Catalogues, going all the way back to the
summer of 1965, my first episode of working with Gerard and Antoinette de
Vaucouleurs.
My curiosity was piqued when I found that IC 520 was included in the Shapley-
Ames Catalogue while NGC 2646 was not. What's going on here, that the
brighter of a pair of galaxies just 12.5 arcminutes apart is an IC object
object while the fainter is an NGC object? Shouldn't it be the other way
around?
In principle, perhaps, but Wilhelm Tempel, the discoverer of NGC 2646, has the
following description for it on the night of 27 July 1883: "Nebel III, klein,
es folgen sudlich, 2 1/2' entfernt, 2 Sternchen 12-13m". In my translation,
this reads, "Nebula [Herschel class] III, small, followed south, 2 1/2' away
[by] 2 stars 12-13m." The two stars are just where Tempel says they are for
the galaxy usually taken as the NGC object; they are very definitely NOT on
the sky near the brighter IC 520.
Even though Tempel's position is flagged by "+-" in both coordinates, and is
indeed not very accurate, the two stars clinch the identification. IC 520 was
not discovered until five years later when Lewis Swift went over the field.
He picked up NGC 2646, too, and also noted the two stars to the southeast.
Because of the poor NGC position, Swift did not realize that his second "new"
object had been discovered earlier. So, it now carries an IC number as well
as the NGC number. See the note on IC 511 for more on that number.
So, here is a case where I simply have to accept that the IC object is the
brighter of the pair. These things happen ...
=====
NGC 2648 has a faint companion seen first by LdR. See the note about it in
the "notngc" files".
=====
NGC 2652 = NGC 2974. Searching for NGC 2652 during work on SEGC, I could not
find it. When I came back to the number two decades later, I tried larger
errors. The galaxy finally showed up one hour later on the sky, and is NGC
2974 which was seen by both WH and JH. Stone's position is otherwise about
3/4 of a minute of time further east, a common error for him and his
colleagues at Leander McCormick. His description is spot-on, including the
9th magnitude star at 240 degrees position angle, 0.8 arcmin distant.
=====
NGC 2653 is a double star. It was found and well-described by Tempel who
placed it 12 arcmin north of NGC 2655. That is very close to the actual
distance, and the identity is not in doubt. (Carlson notes that the Lick
observers corrected the declination to 10 arcmin further north. There is a
much fainter asterism in that position, but it does not have the eye-catching
appearance of Tempel's double.)
=====
NGC 2655. See NGC 2653.
=====
NGC 2662. JH's NPD is 10 arcmin too large. The error was pointed out by Howe
and included in the Notes of the second IC.
=====
NGC 2664, like NGC 2017 (which see), is probably not a cluster -- but it is a
striking object of about a dozen stars. Villanova et al (A&A 428, 67, 2004)
looked at the proper motions, radial velocities, and photometry to see if they
form a cluster -- they almost certainly do not.
Even so, this is an interesting object, and would probably be quite a sight
at the eyepiece.
=====
NGC 2666. JH's description reads only, "The chief * of a coarse cluster."
There is nothing resembling this at his position (08 50 03, +47 03.6; 2000).
Checking the sweep (139 on 19 March 1828) in the Herschel Archives, I found
that JH made at least a two-degree error in his reduction of the NPD; the
correct NPD should be approximately the same as those for NGC 2712 and
NGC 2776, both found later in the same sweep.
This makes it likely that the group of about a dozen stars around SAO 42564
(08 49 47.3, +44 42 16; J2000), which I had found earlier on the POSS1 print,
is indeed the correct object.
-----
Checking the sweep again in June 2016, I found that JH accidentally copied the
reduced NPD of the preceding object in the sweep (a double star) into the
column for the reduced NPD of this cluster. The difference in the NPD index
between the two objects is 2d 21' 18", leading to a corrected position for
JH's "chief *" of 08 38 14.8, 44 40 27 (NPD, 1830) or 08 49 49, +44 42.3
(J2000), very close to the position of the SAO star. The identity of JH's
object with the sparce group is no longer in any doubt.
=====
NGC 2667 = IC 2410, which see.
=====
NGC 2669. There has been -- and continues to be -- some controversy about the
correct identification of this cluster.
JH didn't help much; his observation and description is sparce:
[h] 3140 8 40 +- 143 21 +- Cluster VII class. A L, poor, loose cl of
stars, 10....13m [Sweep] 440
Consulting the observing log gives us no more information than that; the RA
and NPD are still marked "+-", they are properly reduced, and the description
is copied correctly into the CGH. The GC, however, has no indication that the
position is approximate aside from having the "number of observations used"
marked "::". In particular, JH simply precessed the approximate position to
1860 and presented it with the tenths of seconds of time and arc in full view,
just as if it were a micrometric position measured on a superb night with a
state-of-the-art instrument and an expert observer. The only one of these
apparently present was the expert observer, perhaps rushed ... Dreyer simply
followed along, so the NGC has no clue at all that the position is simply an
approximation.
There the matter sat until Trumpler was searching for the cluster in the
early 1930s. He suggested an error of 1 degree in the declination and another
1 minute 40 seconds in RA, leading to Harvard 3, found sometime during the
1920s by Harlow Shapley and his Harvard team. Brent Archinal, in "Star
Clusters" has that whole story, and I can do no better than point you to that
discussion.
Brent's conclusion is, however, awkward in my opinion. He makes Harvard 3 the
core of NGC 2669, with the four 7-8 magnitude stars around it as members.
This is at odds with JH's estimate of the brightest cluster members being
magnitude 10. Even granting Brent's point that JH's magnitude scale could be
off, it was not THAT far off at the bright end. The position and diameters
that I give in the position table for Harvard 3 is only for the "core" of the
cluster. My feeling, without proof, is that the four brighter stars are
unrelated field stars. We can, of course, now check this with photometry and
proper motions.
Furthermore, there IS a scattering of 20-25 stars in the right magnitude range
centered just four arcminutes north of JH's position. I make the collection
12 by 8 arcminutes, and it looks exactly as JH describes it, "A large, poor,
loose cluster of stars, 10th to 13th magnitude." Even giving some credence to
Trumpler's idea, the cluster at JH's position is more in keeping with his
observation, crude as it is.
Finally, a side note. The NGC lists "[al] Sufi" as the original discoverer
of this cluster. This notion, from an 1874 study of al-Sufi's observations
by Schjellerup, is rejected by Glyn Jones in "The Search for the Nebulae"
where he correctly identifies al-Sufi's object as IC 2391 (which see). There
is no trace of IC 2391 in JH's CGH observations.
=====
NGC 2674. Though Ormond Stone had doubts about this object, his RA is just
one minute of time off, and his declination is good. Aside from his note,
"neb?" his estimated magnitude (16.0) and diameter (0.4 arcmin) are
appropriate for the object.
=====
NGC 2678. There is almost certainly no cluster here, just a scattering of
field stars about 35 arcmin southwest of M 67. Nevertheless, WH recorded "A
cluster of very coarsely scattered stars, not rich" on 15 March 1785. His
position is about 30 seconds of time west and 2 arcminutes north of the NGC
position which comes from a mean of JH's four observations.
JH was not very impressed with the field, calling it "a place rich in stars",
"an insignificant cluster," "a very coarse and poor cluster", and finally, "A
poor cluster of 4 or 5 large and a few scattered small stars." His positions
are nearly as scattered as the stars in the field, but generally define two
places within the group: one at the brightest star in the southern part, the
other in the clump of stars at the northeastern side.
Brian Skiff calls it "four m8 *s only", and AH follow along, branding it an
"asterism". Following JH, I make the object a group of four or five brighter
stars with about 15 fainter scattered around an area covering 28 by 17
arcminutes. Brian is right in one respect: Without the enhancement of the
brighter stars, the Herschels would have never commented on the field.
=====
NGC 2684. See NGC 2688.
=====
NGC 2685 is the prototypical "polar ring galaxy" where a disk of material
similar to that in a spiral galaxy is seen apparently orbiting around a
cigar-like structure. See Sil'chenko (1998A&A...330..412S) for more
information and references to earlier papers. There is a splendid image from
a 200-inch plate by Allan Sandage in the Hubble Atlas.
=====
NGC 2686. See NGC 2688.
=====
NGC 2687. See NGC 2688.
=====
NGC 2688 and NGC 2689. I've identified these using LdR's sketch. Though he
saw the two objects on only one night, the sketch is a fair depiction of the
sky in the area of NGC 2684. It also shows the bright galaxy, it shows NGC
2686 to be double in the correct orientation, and it shows NGC 2687 as well;
all in their correct relative positions.
=====
NGC 2689. See NGC 2688.
=====
NGC 2696 may be MCG -01-23-004. The description and declination are close to
those recorded by Stone, though the RA is about 4 minutes of time off.
Stone's RA is further east -- this is in the same direction as many other of
the poor positions from the first two lists of Leander McCormick nebula
discoveries.
=====
NGC 2699. See NGC 2700.
=====
NGC 2700, 2702, 2703, 2705, and 2707 are almost certainly all stars, with 2703
being a double. Found by Tempel (and word of them apparently sent directly to
Dreyer -- I can find no mention of them in Tempel's ten papers), there are no
nebulae near NGC 2699 that he might have seen. The positions given in NGC
fall only near stars. The 2 deg error in the NPD of NGC 2700 is apparently a
typo. The descriptions are reasonably apt for the stars, however. NGC 2700
is within an arcminute northeast of N2699, NGC 2703 is indeed "little
extended" as one might expect of a double faintly seen, N2705 has three stars
following it with which it forms a trapezoid, and N2702 is about 4 arcmin
northeast of NGC 2699. Only NGC 2707 has no additional description (it is
only "eF, S"), but its position is close to a star that might have a faint,
close companion that would enhance its appearance of nebulosity.
So, while the positions are not exactly on the stars, and the identities are
clearly not sure, what little evidence we have suggests that they are
appropriate, if not completely correct.
=====
NGC 2702 is a probably star. See NGC 2700 for more.
=====
NGC 2703 is a double star. See NGC 2700 for more.
=====
NGC 2704 = IC 2424. This is an identity first suggested by Bigourdan who
found and measured I2424 on 18 March 1892. He could not, however, find the
NGC galaxy at WH's position. Since that is just a minute of time preceding
I2424, the brightest galaxy in the area, the identity is almost certain.
Dreyer has a note about this in his 1912 paper and in his Notes to WH's
observations; he, too, accepted the identity of the two nebulae.
=====
NGC 2705 is probably a star. See NGC 2700 for more.
=====
NGC 2707 is perhaps a star. See NGC 2700 for more.
=====
NGC 2708 is probably also NGC 2727, which see. Also see IC 2425 for a brief
mention.
=====
NGC 2719 may possibly be NGC 2724, which see.
=====
NGC 2722 is probably also NGC 2733, which see.
=====
NGC 2724 is most likely UGC 4726 with an error of almost a minute of time in
RA. It's just possible, however, that the NGC number refers to NGC 2719 since
JH found that during another sweep. And U4726 is as far north of JH's
declination as N2719 is south (about 2 arcmin). But N2719 is another 45
seconds west of U4726, so would require a larger RA correction. Thus, my
preference is to set N2724 = U4726.
=====
NGC 2727 is probably NGC 2708 five minutes west at the same declination. I'm
no longer convinced that this is the correct identification, but I can find
nothing better in the area. The RA difference is, within JH's usual errors,
exactly five minutes, and the galaxy could be called "large". However, it is
not "round", but is noticeably elongated.
Another curiosity concerns the next galaxy that JH found in this sweep (number
21 on 12 March 1826, an early sweep), NGC 2733 (which see). The RA for that
is also uncertain, but JH marks it "+-" and has a note, "[RA] between 52m 31s
and 54m 41s" for equinox 1830. This suggests that he had problems of some
sort during this sweep, making it more likely that the RA for N2727 is indeed
off.
-----
I've checked the sweep, where this is number 21. Unfortunately, the left page
is too dimly reproduced in the Herschel Archive to be legible, but there is a
bold entry "Not in Catal". NGC 2733 is number 22 and carries the same "Not in
Catal" entry; it also has a bold entry in square brackets "Query Clock [alpha]
how taken". So, the sweep won't help us until we can examine the original at
the RAS in London.
=====
NGC 2733 is most likely an observation of NGC 2722. JH marks his RA 08 53 00
"+-" and notes "[RA] between 52m 31s and 54m 41s" (for 1830). (His north
polar distance is 93 03 54, also for 1830.) There are, however, no nebulae of
any kind in this RA range that he could have seen.
The declination (from his father's observations) of N2722 is the same, and the
descriptions are not incompatible. Given that JH probably also had trouble
with the RA for NGC 2727 (which see) in the same sweep, this is a likely
identification.
By the way, this is another case where the positional uncertainty that JH
notes in his original list has gotten lost along the way to the NGC. In GC,
the galaxy has its "Number of Observations by H and h" marked "::"; Dreyer
did not carry this over into the NGC, so the position there appears as if it
carries normal accuracy.
Having said that, I have to also say that Dreyer has a note in his 1912
Herschel papers, and in his MN list of NGC corrections resulting from that
collection, about the RA for NGC 2722. Dreyer says that the RA in the GC is
too large by 44 seconds, saying that JH should probably have corrected it (as
he did for other nebulae in the same sweep) to the meridian. This is indeed
true, and the NGC position, corrected by the -34 seconds, lands within 9
seconds of the galaxy.
=====
NGC 2736. On the SERC IIIa-J film, this appears to be the brightest patch in
a supernova remnant that covers most of the 6.4 deg field with delicate whisps
of nebulosity. On the ESO IIIa-F film, however, it is much brighter than the
rest of the SNr, and I wonder if the relatively bright star immersed in it is
exciting it as it passes by. In either case, it is certainly a diffuse
gaseous nebula, not a galaxy.
=====
NGC 2741. Marth's RA is 1 minute too far east. This misled Dreyer into
noting the galaxy as the first of two (the second is NGC 2745, given its
correct RA by Marth). Marth's declination is correct.
=====
NGC 2742. A long time ago, I suggested that this "... is probably also NGC
2816, which see." But it's not. I was struck by the similarity of
declinations and descriptions, so -- without looking carefully at JH's
observations -- lept to an incorrect conclusion. Wolfgang found the correct
answer: NGC 2816 is actually JH's mis-reduced observation of NGC 2820.
=====
NGC 2745. Marth's position is good. Dreyer mistakenly added the note, "f of
2." See NGC 2741.
=====
NGC 2753. The NGC position, from d'A, is one minute of time too large. This
is an improvement over N3575 and N3760, found the same night, which both have
errors of 1 hour in the positions listed by d'A (well, we all have bad nights
...). See them for more.
Speaking of bad nights ... The galaxy is an SB(r)0+ with particularly bright
patches where the bar intersects the ring. In the DSS1 images, the northern
patch is bright enough that both Wolfgang and I mistook it for an interacting
companion. The DSS2 images show us that we were wrong.
=====
NGC 2754. See NGC 2757.
=====
NGC 2757 is probably a triple star. It and two other objects, NGC 2754 and
NGC 2758, were found by Frank Muller at Leander McCormick in 1886 or 1887.
This is one case where the Leander McCormick discovery positions are quite
good, so the identities of N2754 and 2758 with two neighboring galaxies are
not in doubt. However, the third position of Muller's trio falls in a region
where only stars are found.
Herbert Howe, working with the 16-inch at Chamberlain Observatory in Denver
around the turn of the century, noticed a double star near Muller's place.
This is a relatively bright (15th magnitude), wide (12 arcsec) double, and I'd
be surprised if Muller mistook it for a nebula in the 26-inch, even on a night
of rather poor seeing. The 26-inch is optically quite good, and will
certainly show fainter objects with considerably more clarity than any
16-inch, all else being equal.
About an arcminute south-southeast of the double star, however, is a triple
star of about the same total magnitude. The separation of the components is
much less than the separation of the double's two stars. The triple was in
fact picked up as a single non-stellar object by the Guide Star Catalogue
software. My guess is that this is actually the object that Muller mistook as
nebulous. The position, while a minute or so further from Muller's than the
double star's position, is well within the usual Leander McCormick standard
deviation. So, while we can't be certain about the identification (there is
no surviving sketch), I'm going to take the triple as NGC 2757.
=====
NGC 2758. See NGC 2757.
=====
NGC 2760 might possibly be CGCG 350-021 -- there is certainly nothing near
Swift's position that matches his description. In particular, he notes
"nearly between *8 and *9." The stars flanking the CGCG object are at least
two magnitudes fainter, so I don't want to push this identification too hard.
The galaxy is also quite faint, and of pretty low surface brightness with no
nucleus. This does not look to me like a galaxy that Swift could picked up
easily.
Coming back to this in 2014, I wonder if the correct object is CGCG 350-016.
It's about half a degree south of Swift's position, and 1 min 30 sec west.
The stars he mentions would then be at 09 14 18.5, +76 04 08 and 09 14 24.5,
+75 50 53 (both J2000), well within his large 33-arcminute field. This, too,
is a faint galaxy, but the surface brightness is at least "normal", so it
would stand a better chance of being picked up in a sweep. But this also has
to carry at least one question mark -- the position is well off in both
coordinates.
=====
NGC 2783. See IC 2449.
=====
NGC 2786 may be UGC 4861. There is nothing closer to Marth's position that
could be his object, though IC 530 is about 25 arcmin to the southwest of the
nominal position. UGC 4861, however, is closer at about 19 arcmin, is also
somewhat brighter, and more nearly fits Marth's meager description, "vF, vS,
mbM". IC 530 is a pretty flat galaxy which Marth probably would have noted as
considerably extended, but we cannot completely rule it out as his object.
Neither object really thrills me, but I'm going with UGC 4861 for the time
being -- with a question mark, of course. (My thanks to Steve Gottlieb for
prodding me to write a note about this.)
=====
NGC 2789 is also = NGC 3167, which see.
=====
NGC 2804 probably also = IC 2455, which see. The NGC identification is not in
doubt.
=====
NGC 2806 is a star, and is certainly not the galaxy listed in RNGC. It is in
just the place noted by Dreyer in Lord Rosse's observations. Here is Dreyer's
description of the object: "A vF * or cS, eF neb p [N2809] (sky bad),
forming an equilateral triangle with [2807] and [2809] (susp as neb by d'A, =
[N2806])." Dreyer's descriptions and offsets for other objects in the field
are exact, so there is no mistaking the true identity of N2806.
=====
NGC 2807. See NGC 2806.
=====
NGC 2809. See NGC 2806.
=====
NGC 2816. Years ago, I wrote this about NGC 2816:
[This] is probably JH's second observation of NGC 2742. The first came on
8 March 1832 where the galaxy is recorded at its correct position, close to
where his father placed it when he found it in 1790. JH called it "vF, pL,
R, vgbM, 60 arcsec; moon very troublesome. A * 8 m np." (This compares to
his father's rather more interesting note, "cB, E near par., er, bM; 4' l,
2' b. I suppose, with a higher power and longer attention, the stars would
become visible." WH's "er" means "extremely mottled," which leads to his
comment about the stars.)
Just three weeks later, on 30 March 1832, JH swept over the area again, this
time recording a "F, pmE" nebula 13m 30s to the east at the same north polar
distance. There is nothing at that position, a fact first noticed by
Reinmuth in his 1926 "Die Herschel Nebel."
Since the declination is the same, and the description for N2816 appropriate
for N2742, I'm going to suggest that the two nebulae are the same. Even
though the RA difference is large, there is nothing else around that JH
might have seen that makes more sense to me. Still, I'm not convinced, so
I've put colons on the identification.
(At least I had the sense to mark the identity uncertain.)
In fact, NGC 2816 is simply non-existent. The observation that led to it is
indeed one by JH on 30 March 1832, but, as Wolfgang pointed out in March 2014,
that was actually of NGC 2820. In that same sweep, JH picked up, just 45
seconds earlier, another galaxy that he believed to be H II 869 and became
h 576. His second object, h 579, eventually led to the numbers GC 1800 and
NGC 2816.
But the north polar distance for this second object is clearly mis-reduced.
In the log book for the sweep, preserved in the Herschel Archive, we find that
the raw observations for the NPDs, referred to a zero point within the sweep,
read 01 53 18 for h 576, and 01 54 30 for h 579. Yet the reduced north polar
distances for 1830 read 25 02 45 for h 576, and 28 50 33 for h 579, over 3 3/4
degrees apart. (These are the numbers that also appear in JH's 1833
monograph. Only two other objects appear in the sweep, the stars HD 80953 and
81161; their positions are correctly reduced as is that for h 576 = NGC 2814).
Using the difference between the raw and reduced NPDs for h 576 = NGC 2814 as
a guide, the correct reduction of JH's NPD for h 579 becomes 25 01 33. His
position is therefore a good match for NGC 2820, and there is no doubt that
NGC 2816 is identical to this large, faint, edgewise spiral galaxy.
So, the NGC needs fixing: Add the number h 576 to NGC 2814, note GC 1800 =
NGC 2816 as being identical with GC 1798 = NGC 2820, and change the JH number
"576" on NGC 2820 to "579". The NGC positions for the two galaxies are about
10 seconds of time too far east, but are otherwise OK, so there is no doubt
about the identifications.
By the way, the faint companion to NGC 2820, Markarian 108, is not IC 2458
(which see) as I and many others had suggested. The IC object is actually the
northeastern part of NGC 2820 itself. I've retained the alternate designation
for Markarian 108, however, so you will find it listed as "NGC 2820A" in the
big position tables.
=====
NGC 2823. See NGC 2832.
=====
NGC 2825. See NGC 2832.
=====
NGC 2826. See NGC 2829 and NGC 2832.
=====
NGC 2827 = IC 2460, which see. Also see NGC 2832.
=====
NGC 2828. See NGC 2832.
=====
NGC 2829 is most likely the faint galaxy that I've included in the position
table. This is tolerably close to the position shown in LdR's diagram.
On the other hand, LdR's object may be a star, also close to the position in
the diagram. In addition, it is sometimes identified with a faint double
galaxy, but that is exactly on the line between NGC 2826 and NGC 2830 -- in
the diagram, the object is off to the east of that line.
=====
NGC 2830. See NGC 2829 and NGC 2832.
=====
NGC 2831. See NGC 2832.
=====
NGC 2832 is the brightest galaxy in Abell 779, and was seen by WH and JH. The
younger Herschel also picked up another galaxy in the area, as did d'Arrest
-- who also saw three others, measuring two of them -- but it remained for
Lord Rosse's 72-inch Leviathan to reveal the cluster of a dozen or so galaxies
around the brightest. These are NGC 2823, 2825-2834, and 2839. Note that the
identification of NGC 2829 is somewhat uncertain, and that NGC 2827 = IC 2460
(which see).
Lord Rosse made micrometric measurements of only six of these (with respect
to the brightest), but JH received notes from the Earl that allowed him (JH)
to give good positions in the GC for six others. He had to give the remaining
two of the 15 claimed nebulae estimated positions.
In spite of JH's care, the GC is rather confused in the area. When Dreyer
came around to the group during his preparation of LdR's observations, he
sorted the area out pretty well, and the NGC reflects his careful work. In
the process, he dropped two of the GC numbers, and combined two others so that
the total number of nebulae here seen by LdR is just 12 -- the sketch shows
those twelve in their correct relative positions. Only for NGC 2829 (which
see) is there any uncertainty left about the identification.
Curiously, however, Dreyer put WH's observation and the brightest of JH's on
NGC 2830. LdR calls the brightest "alpha", and this is clearly the third of
three in short line in the center of the cluster. Yet Dreyer is apparently
claiming that WH and JH saw one of the fainter galaxies here, not the
brightest (Dreyer of course switches the descriptions as well). I find it odd
that, given his otherwise careful treatment of the area, he should have
misidentified the brightest galaxy, and not one of the fainter. However, his
note in the NGC gives an alternate (and correct) numbering of the galaxies,
showing that he was not convinced that he had it right in the main body of the
catalogue.
Finally, Dreyer has a note appended to the second of WH's catalogues of
nebulae for H I 113: "A second and better obs. in Sw. 549, Mar. 28, 1876, 40
Lyncis, p. 1m 11s, s. 39'." Reducing both this and the observation in WH's
main table shows that this is not a "better" observation, but is further off
in both coordinates than the presumeably "worse" one (09 16 40, +33 57.9 for
WH's first observation w.r.t. 66 Cancri; vs. 09 16 51, +33 57.5 for his
second. The modern position is 09 16 44.0, +33 57 43). In neither case,
however, is there any chance for mistaking the identification of WH's object
for anything but the brightest galaxy in the cluster.
=====
NGC 2833. See NGC 2832.
=====
NGC 2834. See NGC 2832.
=====
NGC 2837 is a double star found by JH on 16 Dec 1827. He mistook it for a
nebula, perhaps on a night of poor seeing, but correctly noted that it is west
of a brighter star. His estimated distance to the star was 8.5 seconds, while
the actual distance is 9.2 seconds, good enough agreement that the identity
can be regarded as pretty certain.
=====
NGC 2839. See NGC 2832.
=====
NGC 2843. In spite of the faintness of this galaxy, and its proximity to the
considerably brighter star, it is almost surely the object that WH found. He
is cautious in his description, noting that it took 240X to show the object
and the star. His position is just an arcminute east, too, well within his
usual observational error.
However, there is some question about this object. WH's description in full,
taken from CH's fair copy in the Herschel Archives, reads, "A suspected
nebula; but No. 4 [240X] shewed some S stars with suspected nebulosity;
probably a deception from want of light and power. 47 ([delta]) Cancri f
36' 0" n 0[deg] 53' RA 9h 9' 18" PD 70[deg] 14'." (CH abbreviates "minutes of
time" with a single quote and "seconds of time" with a double quote.) The
position she gives for equinox 1800.0 precesses to 09 20 34, +18 55.8 for
J2000. Note, too, that WH's published NPD offset is "52" arcminutes north of
47 Cnc, not "53" as CH has recorded.
All considered, I think that WH actually did glimpse the faint galaxy in a
moment of exceptional seeing, perhaps with averted vision. Steve Gottlieb has
dug the galaxy out with his 18-inch reflector (the star at 13th magnitude is
easy). So, I have listed the galaxy plus the star as the probable object that
WH saw, though with a colon to reflect his unresolved suspicions.
=====
NGC 2846 is a double star. This was found by Lord Rosse (or by his observer
at the time, Ralph Copeland) who thought it a star with a very small nebula
nearby. Even though no accurate position is given, micrometric offsets to
nearby stars positively identify the star they thought nebulous.
A few years later, Lord Rosse (or Dreyer, who was then the resident observer
at Parsonstown) reobserved the object, but could see no nebulosity. Instead,
he suggested a very small cluster.
A correction to the position, by Bigourdan, appeared in the Notes to the first
IC. However, there is some error in Bigourdan's observation, since his
offsets point to a blank region of sky. Just north of his position is a 15th
magnitude star; another is just west. He probably saw one or the other of
these. In any case, he missed Lord Rosse's double star, so we have to
discount his correction.
My first thought was to accept the first observation of the single star as
N2846, but Glen Deen pointed out that the two star images are actually in
contact on the Sky Survey. While they would not have been merged on a fairly
good night at the 72-inch, they are still clearly close enough together to
have misled some veteran observers into believing that one star was nebulous,
or that there was a cluster present. Since the NGC itself accepts the second
observation, it seems best to follow that.
=====
NGC 2847 is a faint star superposed on a star cloud in NGC 2848. LdR has only
one observation of it on 15 March 1855, saying only "... F knot np [N2848] and
a triple * nf, B * a little more distant nf". The four stars are just where
LdR describes them, as is his "F knot".
=====
NGC 2848. See NGC 3578 and NGC 2847.
=====
NGC 2854. See CGCG 238-051 in the "notngc" files.
=====
NGC 2856. See CGCG 238-051 in the "notngc" files.
=====
NGC 2857. See CGCG 238-051 in the "notngc" files.
=====
NGC 2863 = NGC 2869, which see.
=====
NGC 2866 is a cluster found by JH. He described it simply as a "Cluster class
VIII. Place of a small compact knot of sts." The knot of stars is obvious,
and the position that I've adopted from ESO is for that knot.
The larger, scattered "cluster" around the central knot is not so obvious.
The dimensions I list are an approximation of the size. It could well be that
the knot is the only real cluster here, while the other stars are simpley
field stars. Astrometric and photometric surveys might resolve the issue.
=====
NGC 2868 is a companion to NGC 2863 = NGC 2869, which see for the story. This
is also Bigourdan 039; see CGCG 097-087 in the "notngc" files for more.
=====
NGC 2869 is identical to NGC 2863. WH found N2863 in March of 1786, and JH
observed it again forty years later. JH used his own position and most of his
description in GC, but took an "average" of his and his father's brightness
estimates: "vF" and "F" became "cF". All this is very close to the position
and description we would make today from the Sky Survey. Dreyer copied this
into the NGC.
In 1885 or 1886, Frank Muller was sweeping across the field. He rediscovered
N2863 and also found a fainter companion which became N2868. As usual, his
positions from the circles of the Leander McCormick 26-inch refractor were so
bad that he thought he had found two "novae" rather than just one. He also
suggested that the RA might actually be five minutes larger than that given in
the table in the AJ paper. But there is nothing in either of his positions.
Herbert Howe sorted all of this out satisfactorily in a Monthly Notices note
which Dreyer quoted succinctly in the Notes to the second IC. Howe also got
the positions correct.
=====
NGC 2871 is a star just north-preceding NGC 2872. Lord Rosse has two detailed
observations of the N2872/4 group, one of which includes micrometrically
measured offsets which point exactly at the star.
=====
NGC 2872. See NGC 2871.
=====
NGC 2874. See NGC 2875.
=====
NGC 2875. This is the north-following part of NGC 2874. Lord Rosse's
micrometrically measured offsets point exactly at the rather knotty spiral
arm, and his description is consistent with the appearance on the First Sky
Survey prints.
=====
NGC 2879 is an asterism of four stars. D'Arrest saw it on three different
nights, and on all three nights he mentioned the 15th magnitude star 11 time-
seconds west. On one night, he also mentions the 9th magnitude star 17 time-
seconds east and 3 3/4 arcmin north. These stars are just where he says they
are, so the identification of the asterism is secure.
=====
NGC 2881 is an interacting pair of spirals seen as just a single object by
Lewis Swift and, later, Herbert Howe. Swift's position is pretty good, coming
from one of his earlier discoveries at Warner Observatory in Rochester. Also
accurate is his comment about the "coarse double star" 17 seconds following.
Howe makes it south-following, but Swift is more nearly correct.
=====
NGC 2883. There is no puzzle about the identification, or about the fact that
JH got it wrong when he called it "A vF, S,[sic] cluster, class VI; vglbM;
resolved so as to see the stars which are 15 m ..." On the other hand, he
continued, "... almost to be called a vF, large nebula" -- this is more nearly
correct for this peculiar galaxy.
Just what the object actually is, however, is a bit uncertain, at least just
looking at the image on the DSS. While I called it an "Im pec" in SGC, I
wonder now if it isn't an interacting system. There could be as many as three
separate galaxies here, so I give positions for all of them.
=====
NGC 2885 = IC 538. John Herschel saw this on only one night. The RA is
marked with a plus-minus sign, and his description reads, "eF, vS, E in
parallel; RA very uncertain." His description is correct, and his RA is
indeed about 25 seconds too large (there is nothing in his estimated place,
not even a star). The comment "... E in parallel ..." (that is, the
position angle is 90 deg) fits no other galaxy in the area. This is also the
brightest galaxy around, so the identification is secure.
Bigourdan made four observations of his "nova" Big. 154, the object that
became the IC galaxy -- his reduced position is right on NGC 2885 itself. He
also claims to have glimpsed "NGC 2885" (on one night only; on another night,
he has this as "Non vue" [not seen]) about 1.4 arcmin north of JH's place.
But as with JH position, there is nothing there, not even a star.
Finally, R.S. Ball saw this galaxy and two companions on 10 January 1867. The
story is told in the "notngc" files.
=====
NGC 2886 is probably the asterism of 4 stars about an arcminute following JH's
position. There is nothing else in the area that fits his sparce description,
"eeF; 50[arcsec]" from a single observation. ESO does not give an
identification for the object, but simply gives the nominal position and a
question mark for the object type.
=====
NGC 2888 is a fairly bright galaxy just where JH found it during his time at
the Cape of Good Hope. The Galactic latitude is fairly low (16 degrees), so
it should come as no surprise to find a streamer of Galactic diffuse
nebulosity superposed on the galaxy. Yet on the DSS images, the juxtaposition
is striking. The background is rich in faint galaxies which simply adds to
the interest of the field.
=====
NGC 2897 has a beautiful companion galaxy with a nearly circular ring, almost
exactly centered on the nucleus. These ring galaxies are relatively rare, but
can be pretty well-explained by the face-on, centered collision of two
galaxies. Theys and Spiegel (in ApJ 208, 650, 1976) were among the first to
try to explain these ring galaxies in terms of a collision, and their model
has held up reasonably well over the years.
=====
NGC 2901 may be one of the galaxies (UGC 5070, 5074, or 5087) just over a
degree south of Stone's especially crude position, estimated during a search
for Winnecke's comet. There is nothing closer to his position that he might
have mistaken as nebulous, unless it is one of the faint double stars in the
area. Wolfgang has taken one of these, but I do not think that it appears
especially non-stellar: One star is 13th magnitude, the other is 16th, and
the two are separated by 16 arcseconds. Not a strong argument against these
particular two stars, I admit, but there are many galaxies within two degrees
of Stone's position that would be better candidates.
Other objects worth a mention include NGC 2918 and CGCG 152-030, and there are
many fainter CGCG galaxies as well. Without seeing Stone's original observing
log, however, I think we are stuck with no viable candidates for this one.
And even if Stone's log has other clues, why did he not pass them on to us?
=====
NGC 2902 is not IC 543 (which see for details) as suggested in MCG.
=====
NGC 2903. The nuclear region is patchy with several bright knots, probably
star-forming HII regions, though generally refered to as "hot spots" in the
literature. Rather than choose one as the "nucleus", I've taken the average
of the five knots seen picked out by the 2MASS Point Source software within 12
arcsec of the brightest knot. This seems to be reasonably representative of
the 15 accurate positions that I've collected up to May 2014.
Also see NGC 2905 for the story on the northeastern arm of NGC 2903.
=====
NGC 2905 is the northeastern arm of NGC 2903. JH has several observations of
it in that position, as well as a sketch. The only slight mystery here is why
WH made NGC 2905 one of his first class nebulae, ranking it in brightness with
the central portion of NGC 2903 itself. I certainly never saw it that way in
telescopes ranging in size from 6 inches to 30 inches.
Fixing a position is a bit uncertain, too. There is a bright star cloud in
the arm that is well-represented in the sky surveys by its brightest knot.
However, that knot is somewhat to the east of the center of that part of the
galaxy sketched by JH and LdR. So, I have adopted the mean value of seven
knots from the 2MASS Point Source Catalog -- this position seems to be pretty
representative of the part of the galaxy seen by the earlier observers.
=====
NGC 2908. WH's position, reduced by CH and given in her fair copy of the
Sweeps, lands closer to a double star than it does to the faint spiral that is
usually taken as H III 977. This has led me to wonder whether WH might
actually have picked up the brighter double star rather than the fainter
galaxy.
However, Dreyer (in his Notes to WH's catalogues in the Scientific Papers)
notes the offsets from another star in the sweep. These give a position
closer to the galaxy than to the double star. Dreyer also notes that
Bigourdan's observation accords better with the position derived from this
second star (Bigourdan certainly saw the galaxy on the one night he measured
it; on a poorer night a few years later, however, he was unable to see it).
All these positions are in the big table, credited to WH and Bigourdan as
appropriate.
Given that the second star is closer to the galaxy than the first, we should
probably give it greater weight than the first when deciding on a position
derived from WH's observations. The position from that second star is just an
arcminute north of the galaxy; the double star is several arcminutes to the
northwest. Thus, I'm pretty sure that WH did in fact see the galaxy, faint as
it is.
His full description, by the way, reads "eF, vS. I also saw it with 300.
iF." The "iF", omitted from the GC and NGC summary descriptions, may also be
relevant. The faint galaxy has two fainter stars superposed on it which may
have lent the impression of "irregularity."
=====
NGC 2909 is a double star about 30 arcsec following JH's position. Several
observers have suggested other identifications for it, but nothing else in
the area is as convincing. See also NGC 4512 for more on the sweep in which
JH found this object.
=====
NGC 2910. JH has three observations of this cluster, two in April 1834, the
third on 5 January 1837. The positions scatter over nearly a minute of time,
and three minutes of arc. Assuming that the second observation has an error
of -1.0 minute in RA, that and the third observation are reasonably accordant.
Since the NPD of the first observation is marked uncertain, and since the RA
for that is well off the others, I've left it out of the mean position I
calculated for the cluster. JH simply took the positions at face value and
used them all for a mean that is about 16 seconds of time west of the
cluster's apparent center. That is the position that appears in the GC and
NGC.
All this is not to suggest that there is doubt about the identity -- there is
not. JH's descriptions are accordant with what we see on the sky, and are
internally consistent, too. Only his positions have the minor problems noted
here.
=====
NGC 2911. See NGC 2912.
=====
NGC 2912 is a star described only in Schultz's note for his observation of
NGC 2911. The faint galaxy close following N2911 (taken as N2912 by all and
sundry) is much too faint for Schultz to have picked up with his 9.6-inch
refractor, especially given the considerably brighter star just a few arcsec
following (the 1950 position for the star is 09 31 12.07, +10 22 57.2).
Brian Skiff has suggested that N2912 is identical to N2914. But Schultz has
observations of both objects on the same three nights, calling N2914 nearly
as bright as N2911. Furthermore, Schultz's description of N2912 "eF, f h608
[N2911] some seconds, ab[out] 2' n, but not observable" places his "nova"
northeast of N2911, not southeast.
The only object in the area, bright enough that he could see, that matches his
estimated offsets, is the star that I list in the table. This may not be a
completely solid identification, but it is pretty close.
=====
NGC 2914. See NGC 2912.
=====
NGC 2915 is a nearby "dwarf" (more properly, a "sub-giant") galaxy. Its face
is nearly uniform on the IIIa-J blue DSS image, but there is an apparently
eccentric nucleus seen on the IIIa-F image. All of the positions in the table
refer to this nucleus.
Courtney Seligman's image of it includes the tremendous neutral hydrogen disk
that extends many diameters of the galaxy itself beyond the optical
boundaries. It is a spectacular demonstration of the power of non-optical
methods to show us previously unseen parts of the universe.
=====
NGC 2918. See NGC 2901.
=====
NGC 2925. JH's position refers to a double star southeast of the center of
the cluster. But there is apparently a further +20 time-second error in his
RA which puts his position nearly half a minute east of our modern ones.
=====
NGC 2932 is a patch of the Milky Way about 1 degree across, centered near JH's
approximate position (he gives it only to a full minute of time and a full
minute of arc). In his description, he notes that it is "... a degree or
degree and half in diameter, very rich in stars of all magnitudes from 8 m
downwards ..." This is just what we see on the IIIa-J plate today.
=====
NGC 2938 was the first of fifteen nebulae found by WH in sweep 1096 of 2 April
1801. There was considerable confusion in the 19th century about the
identities of these galaxies, confusion still not sorted out at the time the
NGC and the ICs were published.
It was, however, mostly laid to rest in an unsigned note in MNRAS 71, 509,
1911 "Communicated by the Astronomer Royal". This gives accurate positions
for forty nebulae in the area covered by WH's sweep, and enabled Dreyer to
finally publish (in the Scientific Papers) corrected NGC identifications for
WH's galaxies.
Dreyer, however, did not give cross-identifications to all of the NGC numbers,
particularly those which came in from other observers (JH and d'A). I list
those in my note to NGC 3752 (which see), where I give a fairly detailed
account of the problem and its solution.
NGC 2938 itself has been taken as not just the galaxy UGC 5115, but as the
star that JH observed near his father's published position. This, in fact,
was Dreyer's preference expressed in the 1912 Monthly Notices paper where he
published corrections to the NGC based on his work on WH's lists for the
Scientific Papers.
However, because it is clear that WH did in fact see the galaxy -- once his
observations are corrected for the telescope misalignment, his position agrees
with that for the galaxy -- I have chosen to assign the number to the galaxy.
I have to stress, however, that this is just one interpretation of the
historical record. See NGC 3752 for more on all of this.
Finally, while well-aware that WH actually did see the galaxy, Courtney
Seligman originally chose in June 2015 to adopt Dreyer's identification of
JH's star as the correct one for NGC 2938. Here, Courtney made the reasonable
assumption that Dreyer's own corrections to the NGC represented the best way
to present the catalogue today.
I, however, have made the assumptions that Dreyer was primarily compiling and
summarizing the known observations, and that -- had he had the advantage of
today's deep sky surveys -- would have tried to give the objects actually
listed by the original observers. For almost all of the NGC objects, the two
different ways of correcting the errors will lead to the same objects. This
is obviously not the case for NGC 2938 and a few others.
While I clearly favor the second viewpoint, I've given both objects -- WH's
galaxy and JH's star -- in the big table under NGC 2938. See the notes for
h 612 (JH's star) for more on this.
=====
NGC 2944. It has seemed strange to me that just three arcmin north-following
this triple galaxy is a considerably brighter pair. Did Palisa perhaps see
one of the pair rather than the galaxy we now call N2944?
Tracking down Palisa's original observation to AN 2782, I found that his
micrometrically measured position (based on six settings) falls within
three arcsec of the GSC position of brightest of the triple. The identity is
thus certain -- but why did Palisa not see the brighter galaxies just to the
north?
=====
NGC 2947 = IC 547 = IC 2494 is the only object that I am currently (May 2003)
aware of which has an entry in all three of Dreyer's catalogues. See IC 547
for details.
=====
NGC 2951 was not described as double by Marth, but his "pF, S, E" is a fair
description of the two galaxies as they might be seen visually. Given that
Marth's position is within 3/4 of an arcminute of the pair, the identity is
certain.
=====
NGC 2952. There is no sketch, so all we have to go on are the crude position
and relatively detailed description that Muller has left us in the second
paper from Leander McCormick. In particular, Muller has a 9.5-mag star
following the nebula by 30 seconds. His full description is "Mag." = 15.5,
"Size" = 0.6 arcmin, "Form" = iR, "Condensation" = sbM, and "Notes" = *9.5,
f 30[seconds].
For SEGC, I chose a faint galaxy preceding an 11th magnitude star by about 30
seconds (the star is at 09 38 06.4, -10 11 40 for J2000). The star would have
appeared brighter in the big Leander McCormick refractor, so the magnitude
difference is not very bothersome. Also the RA of the galaxy is about 2
arcmin west of Muller's estimate, a common offset in these two Leander
McCormick lists. There is also a star superposed just southeast of the
nucleus; this would have made the object somewhat more noticeable during
visual sweeping.
While all this suggests that I've picked up the correct galaxy, I do have to
put colons on the identification. We would need a sketch to be sure.
=====
NGC 2953 is probably the star about 6 arcmin south-southeast of NGC 2954. JH
found both during one of his rare excursions north of the equator during his
South African sojourn on 18 March 1836. He says of this, "Suspected nebula.
(N.B. These suspicions have been so constantly verified on reobservation,
that I have little hesitation in registering it as an object in the
catalogue.)" He adds in his description of NGC 2954, "Another suspected 6
arcmin south, nearly on the same meridian."
JH gives the position only to a full minute of time and a full minute of arc;
the seconds are missing in both coordinates. The star is almost strikingly
isolated -- there is no brighter star within 4-5 arcminutes of it, and no
galaxy or nebula aside from N2954 nearby, either. While we can't be
absolutely certain about the identity -- the approximate position erodes
confidence -- the lack of any other candidate matching JH's description lends
considerable credibility to the star.
=====
NGC 2954. See NGC 2953.
=====
NGC 2957 is the brighter of a pair of galaxies, or perhaps the pair itself.
JH describes it only as "eF; has a * 13 m near," and his RA is one minute of
time too small. But his object is clearly identified by the star, as well as
its proximity to NGC 2963 which shares the RA error.
The fainter galaxy is Markarian 121, so has received somewhat more attention
than its brighter companion. This probably accounts for the RC2 designation
"N2957A" for the fainter object, and "N2957B" for the brighter.
=====
NGC 2959. JH says this "is s of a S grp of sts". There are indeed 6 stars
about 8-9 arcmin north.
=====
NGC 2961 is sometimes called "NGC 2959A" following its designation in Keenan's
ApJ 82, 62, 1935 paper.
=====
NGC 2963. JH's RA is in error by -1 minute of time, an error shared by its
neighboring galaxy (the brighter of a pair), NGC 2957 (which see).
=====
NGC 2972 = NGC 2999, which see.
=====
NGC 2973 is perhaps the triple star just following JH's position. If it is
indeed the correct object, JH's note "a B * 8 m follows" is somewhat
misleading since the star is clearly south-following. That raises the
possibility that the double star also listed in the table is JH's object.
However, JH describes his object as "eF, 40 arcsec." The triple is closer
to that size than the double. So, both asterisms are candidates. For the
present, I favor the triple -- but not by much.
I also note that the two eastern stars of the triple have close companion
stars. So, the triple is actually a quintuple, or as I've simply written over
the years, an "asterism".
=====
NGC 2974 is also NGC 2652, which see. Also see NGC 3382 where NGC 2974 may
figure in the identification of this questionable object.
=====
NGC 2977 was one of the galaxies found by WH on the night of 2 April 1801 for
which large, systematic errors exist in the position. See NGC 3752 for more
information.
=====
NGC 2979 = NGC 3050, which see.
=====
NGC 2982. JH had trouble with the position of this cluster. The NPD printed
in CGH is corrected on the errata page of CGH, and even that corrected NPD is
about 10 arcmin south of the scattered group that we've all taken to be his
object. That the correction is necessary is confirmed by checking the sweep
in the Herschel Archives: the north polar distance printed in CGH belongs to
the next object in the sweep, a star. Otherwise, the position looks to be
correctly reduced.
However, JH's description is of some help: "A cluster of about 20 stars 11 m,
and 2 of 10' [10.5] m, forming an oblong nearly in parallel; place of
preceding * 10' m." This fits the appearance of the modern identification
pretty well, though I do not see a "preceding * 10'".
For lack of anything better, we'll go with this object for now.
=====
NGC 2984 = IC 556, which see.
=====
NGC 2986. WH saw a companion, ESO 566-G004, to this object. See that in the
"notngc" files for more.
=====
NGC 2995 appears to be a clump of stars roughly 20-25 arcmin across centered
about 10 arcmin north of JH's position. His description reads "Cluster VIII
class, at least 20 sts 11 m and upwards, and many smaller." This is what we
see on the IIIa-J plate, though I doubt that it is a real cluster.
-----
That was how I described the "cluster" in 1997. Looking at it again in May of
2014, I see a much smaller clump (8' x 5') centered at much the same place.
There are possible extensions north and east to a size of roughly 20' x 20',
much the same as I previously saw, but centered at 09 43 50, -54 33.2 (2000).
This time around, I am happier with the smaller "cluster", so that is the one
that I've put into the table. This clearly needs visual confirmation.
JH, by the way, adds "fully [qualified?] to be called a cluster" in his sweep
(784 on 5 April 1837). He uses similar phrases now and then for other
clusters about which he apparently has some nagging doubt. In this case, the
doubt is evident.
=====
NGC 2996. JH's RA is well off and the star an arcminute following is 9th
magnitude, not 20th as noted in CGH. An interesting pair of errors ...
=====
NGC 2998. See NGC 3000, 3002, 3004, and 3008.
=====
NGC 2999 = NGC 2972. JH's place for N2999 is only approximate. He says,
"Observed for Dunlop 397, and place only rough. Possibly the same object
with Sw 680, No. 27, which see above (No. 3183 [= N2972])." This is an
entirely reasonable hypothesis, and JH's descriptions are the same, so I've
adopted the identity.
=====
NGC 3000 is a double star, accurately located by Dreyer's own micrometric
observation referred to NGC 2998. He also measured NGC 3005, 3006, and 3008
on the same night (1 April 1878) with LdR's 72-inch.
=====
NGC 3002 is a star. It and NGC 3004 were found by LdR with his 72-inch, and
are both included in his chart of the NGC 2998 field. Of the three faint
stars near the place shown for NGC 3002, the brightest (included in the main
table) and closest to Dreyer's position as sketched, is most likely the one he
saw. The second brightest star is at 09 45 52.0, +11 17 34 (B1950.0); or at
09 48 33.0, +11 03 35 for J2000.0.
MCG +07-20-052 is a low surface brightness interacting system less than 2
arcmin southeast of the star. MCG unfortunately took this to be NGC 3002, so
the object has been incorrectly saddled with the NGC number ever since.
=====
NGC 3003 is a big, nearby, late-type spiral with a line of 4-5 knots in the
middle of a relatively faint bar. The brightest knot is the western-most; it
may have a star superposed, or it may be the actual nucleus. Whatever the
case, that is the knot I've taken as the nucleus of the galaxy. I have given
positions for the second- and third-brightest as well, so if one of them turns
out to be the actual nucleus, we still have the galaxy pinned down.
=====
NGC 3004 is, like NGC 3002, a star. LdR saw it only once, and included it on
his chart, though did not letter it: it should be "alpha," between NGC 2998
and NGC 3005.
=====
NGC 3005. See NGC 3000 and NGC 3004.
=====
NGC 3006. See NGC 3000.
=====
NGC 3008. There is no doubt about the identity of this galaxy. It is
included in a sketch in Lord Rosse's big 1880 monograph, and was measured by
Dreyer himself on 1 Apr 1878 while he was examining the area around NGC 2998
(he used this as a reference object for his measurements).
However, of the four galaxies he measured, it is the furthest from N2998, and
he has given the position angle to only a full degree, and the distance to a
full arcsecond. The other three objects have an additional digit in each
coordinate. Reducing the positions, we find that this one is the furthest off
the true position on the sky, and I wonder if Dreyer didn't make an error of
some sort here. If, for example, the position angle is 83 degrees rather than
88 as Dreyer has it, the position of the galaxy comes considerably closer to
the truth (the distance he gives is 552 arcseconds).
As I said, though, the identity of the object is not in doubt.
=====
NGC 3009. The identification is uncertain. See NGC 3010 for the story.
=====
NGC 3010. There are three galaxies here that are occasionally numbered "NGC
3010A", "NGC 3010B", and "NGC 3010C" (though I have deleted these suffixes
from the position table; they made the table very difficult to read. For the
record, "N3010A" is the middle galaxy, "N3010B" is the southwestern, and
"N3010C" is the northeastern). JH's position is far enough off that it does
not help, at least in an absolute sense, in identifying his object.
However, his position for NGC 3009, seen in the same sweep and called "The
first of 2" -- NGC 3010 is "The second of 2" -- is also off: the RA
correction is +17 seconds, and the Dec correction is -1.6 arcmin for NGC 3009
if we take the larger and brighter (though lower surface brightness) spiral
five arcminutes southwest of the triple as the first of the pair that JH saw.
Applying these corrections to JH's position for NGC 3010 gives 09 50 17,
+44 19.2 (J2000), still about 20 seconds of time west of the triple, though
the declination has fallen in line.
The problem with this is that the position for NGC 3009 is far enough off to
throw its identification in doubt, too.
So, how about JH's descriptions? As published, they read for NGC 3010: "F,
psbM, r, stars seen. The second of 2." The "r, stars seen" could refer to
the nuclei of the three galaxies. (But there are also a few faint stars to
the north that JH might have picked up.) For NGC 3009, his published
description reads "Not vF, R, bM, r. The first of 2." These -- setting aside
"The first/second of 2" -- unfortunately are generic enough that they could
fit any of the four galaxies.
Finally, it is also possible that his observations here actually refer to two
of the three galaxies of the triple. JH's RAs support this in that he has
only six seconds of time between his two objects, the same difference as
between the western and eastern galaxies of the triple. His declination
difference is 1.5 arcmin, while the declination difference between the eastern
and western galaxies of the triple is 1.0 arcmin, certainly within his nominal
error bars.
While my own inclination would be to select the two brightest galaxies of the
triple as JH's pair, I don't think that he has left us quite enough to go on
to select any two of the four galaxies as the ones his observations refer to.
Unfortunately, this means that I am going to leave the "traditional"
identifications in place, but with question marks on them. Not very edifying,
I know, but there it is.
-----
There things stood until May 2015: Courtney Seligman wrote about these two
objects, saying essentially that he was not happy with the traditional
identifications (this makes at least two of us!). This led me to check JH's
sweep in the Herschel Archive. He has a note attached to his 17 March 1828
observation of the two nebulae: "Something unaccountable in the taking of the
RA's here John[??] must surely mean[??] +12- -43 in the 2nd obs." The actual
RA observation for the 2nd object reads "-12 -43", where the first number is
found in the column where the minutes of RA on the clock is usually written.
The "-43" is perhaps the chronometer correction (which JH calls the "beat"),
though the minus sign is stronger than usual, and is in the column usually
reserved for the seconds of time on the clock. I can see why JH was puzzled
when he came to reduce these observations! My own guess is that the "-12" is
seconds of time, and the "-43" is simply a repeat of the "beat" for the first
object.
JH's descriptions from the sweep are "a pair" with a bracket around that, and
a simple diagram showing the two objects at roughly a 30 degree orientation
with respect to one another, assuming horizontal on the page is east-west. If
south is at the top in this diagram, then the brighter nebula is to the
southwest. The next object in the sweep is the double star at 10 01 25.4,
+44 58 09 [J2000]; its diagram has the same orientation as the diagram of the
nebulae. On the sky, the orientation is southwest-northeast just as the
nebulae are oriented. The description for the first object reads "not vF, bM,
R, r, gbM". There are indeed two "bM" notations, probably to distinguish it
from the second object, which is described as "F, resolvable, stars seen,
psbM."
Looking at the observation of the first nebula in the sweep, I see that it
reads "9 39 50 -43" and is perhaps referred to the second wire (though the "2"
is very close to being a flat line; perhaps it is not the second wire, but the
first, the trailing edge of the field, or even a "null". I see other "2"s in
these sweeps written the same way, but this is most extreme example I've
noticed). The second nebula is definitely referred to the second wire; if so,
the two RAs ought to be directly comparable. The NPD index for the first is
"2 39 30", and for the second "1 1/2' north". For the star "15 Leo Min" --
observed just before the two galaxies -- JH has "9 37 15 -14" for the clock
and chronometer beat, wire "1", and "0 56 55" for the NPD.
All this implies offsets between the star and the first galaxy of +1m 27s and
-1d 42' 35" which gives a position of 09 49 51, +44 18.6 (J2000), in close
agreement with JH's own published position 09 49 54, +44 19.3 (precessed to
J2000). If, however, we assume that the wire was mistaken and that wire 1 was
the actual wire that JH used for the transit, then the RA offset becomes
+2m 13s, and the J2000 position is 09 50 36, +44 18.6, close to the first
galaxy in the triplet, MCG +07-20-065. This would imply that JH's second
nebula is within 12 seconds of this one and 1.5 arcminutes north. This
suggests that MCG +07-20-067, the northeastern galaxy in the triplet, is JH's
second nebula. This, however, is the faintest of the three (see Steve
Gottlieb's observations below).
On the right-hand page where JH normally gives the reduced positions, he has
another note, "Must be re-reduced". Under that are the two positions for the
objects that became NGC 3009 and NGC 3010: "9 39 1:, 44 53 50" and "9 39 7:,
44 52 20" (RA and NPD 1830 for both). Just to the right of those is another
column headed "Re reduced [sic] See Red. Book". The positions in this column
read "9 39 6.4, 44 53 34" and "9 39 12.4::, 44 52 0:". These latter positions
are those that JH published in his 1833 catalogue, but the published positions
do NOT carry the uncertainty symbols.
Putting all this together, I am going to suggest that JH observed two of the
three galaxies that we in the past called "NGC 3010", perhaps the southwestern
and the northeastern. These are separated only by 6 seconds in RA and a
minute of arc, less than JH's estimates (assuming that the "-12" for the
second object is indeed a difference in RA of 12 seconds), so I am obviously
not going to insist that this is correct. His descriptions are puzzling, too,
but as I mentioned above, they might be understood if he glimpsed the third
galaxy and some of the nearby stars.
[Wolfgang suggests that the "-12" is a chronometer difference; if so, the
six second difference in RA matches JH's measurement given the two beats per
second of the chronometer. I'll have more to say about this below.]
What about the galaxy traditionally called "NGC 3009"? This is bracketed by
JH's RAs from the two different wires with the declination being about an
arcminute south. However, a 12 second and 1.5 arcminute difference to the
second galaxy from this one works pretty well in declination, but not in RA.
And while the western-most galaxy of the four, MCG +07-20-062, is larger, it
has a lower surface brightness. Given the similarity of JH's descriptions for
his two objects, I'm a little less happy with the idea that he saw this one
and just one of the other three. But again, see Steve Gottlieb's notes that
I've quoted below.
So, I offer two of the galaxies in the northeastern triplet as a reasonable --
though obviously questionable -- interpretation based on the information in
JH's sweep.
Finally, Courtney's discussion has led me to look into other observations of
the galaxies here. LdR reports two observations of the area. The first is
from 1 March 1854, presumably by R.J. Mitchell who writes "One pB; 6'f and a
little north are two others vF, about 3' apart pf; several others round
about." (We'll come back to the "several others" in the addendum below.) On
1 April 1878, Dreyer at the eyepiece has "1933 [N3009] and 1935 [N3010] seen
for a few minutes ..., the f one is smaller and in a rectangular [triangle] of
3 sts." These are pretty clear descriptions of the two brightest objects, the
ones that we have taken as N3009 and N3010.
On 17 Mar 1895, Bigourdan has micrometric observations of the two brightest
galaxies in the area, MCG +07-20-062 and -065. In his description of
"NGC 3010", he mentions "A star, even fainter than this object, is at P =
20deg, d = 0.'7." This "star" is actually the middle of the three galaxies.
In June of 1991, Steve Gottlieb observed the objects with his 13-inch
reflector. His notes:
UGC 5264 = MCG +07-20-062: "F, S, R, even Surf Br"
MCG +07-20-065: "vF, S, R"
MCG +07-20-066: "vF, S, R"
MCG +07-20-067: logged as a mag 15.5 "star".
[O]f the 4 objects MCG +07-20-067 was the least obvious to me -- in fact, I
recorded it as a dim star in my notes. Although MCG +07-20-062 has a lower
surface brightness than -065 or -066, I think it was at least as obvious due
to its larger size. This suggests that MCG +07-20-067 was less likely to
have been seen by JH.
So, we need to take all this into account, too. Bigourdan saw three galaxies
here, but took one to be a star, while Steve picked up all four, but like
Bigourdan, saw one as a star.
In the end, I've arrived at the really messy identification list shown in the
position table. Summarizing, here is how I've broken it all down:
NGC Alternate RA (J2000) Dec Obs Notes
IDs
3009 09 49 54 +44 19.3 oJH As published.
3009 09 50 36 +44 18.6 oJH Assumes wire 1, not wire 2.
3009:: +07-20-065 09 50 33.2 +44 18 52 c2MSP = NGC 3010sw = NGC 3010B
3009? +07-20-062 09 50 11.1 +44 17 42 cSDSS
3010 09 50 00 +44 20.8 oJH As published.
3010 09 50 48 +44 20.1 oJH Offset from N3009, wire 1.
3010:: +07-20-067 09 50 39.4 +44 19 52 c2MSP = NGC 3010ne = NGC 3010C
3010? +07-20-066 09 50 34.6 +44 19 24 c2MSP = NGC 3010m = NGC 3010A
There are still other ways to interpret JH's observations (why, for example,
did he make the RA difference just six seconds when the log book has "12"?
Did he perhaps take that as a difference in the chronometer "beat" rather than
as difference in seconds of time? Wolfgang, as I've said, agrees with this
interpretation), so this is not the final word here.
At least we know that JH saw two of the four galaxies here -- but which two,
we just aren't sure. As before, not very edifying, but the observations just
don't pin JH's objects down any better than this.
-----
Another note in September 2015: I had an email from Wolfgang (mentioned
above) that suggests this sequence of events that might account for JH's
records here:
1) JH saw the first nebula -- call it "N1" for brevity -- nearly in the
center of his field when the clock read 09 39 50. It had already passed
wire 1, and took another 43 chronometer beats (= 21.5 seconds) to reach
wire 2.
2) Another 12 beats later (6 seconds), the second nebula crossed wire 2
1.5 arcminutes north of N1.
So, Wolfgang's interpretation is that JH's strange notation "-12 -43" means
that N2 follows N1 by six seconds, and that N1 was in view for 21.5 seconds
before it crossed the second wire. This is reasonable given that the field of
view is just over 90 seconds of time wide at this declination, and that the
separation of wires 1 and 2 is 45.3 seconds. This leads Wolfgang to say "The
short distance N1-N2 speaks against the identification [of] NGC 3009/10."
In other words, UGC 5264 = MCG +07-20-062 is NOT NGC 3009. Wolfgang goes on
"So we must choose two of the components of the MCG triple (7-20-65, -66,
-67). [But Steve Gottlieb has shown that] only the first two [of these] are
bright enough -- but they are much closer [just 1.5 seconds] than JH's value."
Wolfgang goes on to ask about the issue of JH's description of N2:
"resolvable, stars seen". "What are the 'resolvable stars'? Perhaps JH has
seen [MCG +07-20-0]65 as N1 and 66/67 plus the scattered stars around as N2.
But this is a matter of 15th magnitude!" Wolfgang is right -- these would
have been right at the limit of JH's telescope. Yet JH's description of N2's
brightness is just "F", not "eF" or even "vF".
Wolfgang ends by saying "But facing JH's possible error, N1 = ... NGC 3009 =
UGC 5264 and N2 = ... NGC 3010 = [MCG +07-20-0]65 (or 66) could indeed be the
correct identification!"
-----
And a curious addendum: Looking at the GC, we find that JH includes not just
his two nebulae, but has two other entries, GC 1936/37, which he credits to
LdR, describing them only as "Several near", and giving a single position for
the two "9 41 +-", "45 0 +-" (1860, NPD). Coincidentally, there are only two
galaxies in the area aside from the two that JH observed. It is quite
tempting to assign these two GC numbers to the two spare galaxies. If we do
this, assuming that my double-coloned identifications are "correct", the two
left-over objects are MCG +07-20-062 and MCG +07-20-066. (However, they could
well be two others!) See the "notngc" files for a bit more on this.
=====
NGC 3024. See IC 567.
=====
NGC 3031 = M 81. This is one of the few bright, nearby galaxies that has a
strong, compact radio source in its nucleus. As such, it is one of sources
that define the International Celestial Reference System, the system of
positions on the sky upon which all of astronomy and astrophysics rests.
There is good reason for the branch of astronomy dealing with positions --
astrometry -- to be also called "fundamental astronomy."
=====
NGC 3034 = M 82. The position for this large, bright irregular galaxy depends
strongly on wavelength. The brightest optical knot is not coincident with
the radio "nucleus" nor with the brightest infrared knot. And there are
several bright X-ray sources scattered throughout the galaxy. The position
I've finally chosen is the brightest 2MASS point source in the H and K bands.
It looks like a good compromise position and represents the galaxy well
enough.
All the positions I've listed, though, fall within the boundaries of the
galaxy, and there is of course no identification problem. But note that this
is one of the few Messier objects which also received a number -- IV 79 -- in
WH's catalogue. I've found it curious that WH put it in with his "planetary"
nebulae, but it is the last of that class that he found. It was actually
published, along with seven other of WH's unpublished nebulae, by JH as an
appendix to his (JH's) list of nebulae and clusters in the CGH observations.
=====
NGC 3040 is a triple system, though Stephan only measured and described the
brightest. Holmberg has the brightest two in his catalogue of double galaxies
from 1937, though does not note the NGC number. His number is Ho. 148 for the
pair; Ho. 148a is NGC 3040.
=====
NGC 3046 may be NGC 3051. But if it is, JH has made some strange mistake
since he specifically says in a note in the GC "h3199 [N3046] and 3201 [N3051]
are also distinct nebulae, and were observed consecutively in sweep 562 (h)."
His CGH observation has the note "RA precarious; a hurried observation," and
the Sweep itself, preserved in the Herschel Archive, has the RA marked with a
double colon "::". Otherwise, this observation and that for NGC 3051 just
following are properly reduced and unremarkable.
I'm inclined to believe that the two observations refer to the same object, in
spite of JH's protestations to the contrary. The descriptions are identical
(as far as they go; N3046 is noted only as "pF,R" while N3051 is "pF,S,R,gbM;
20 [arcsec]"), and the positions are not all that much different. There are
two very faint double stars near JH's position for N3046, but they are much
fainter than N3051 and any other double star that I know that JH has mistaken
as a nebula.
This sort of mistake -- measuring the same galaxy twice in the same sweep,
thinking it a different object -- has occured at least twice in his father's
sweeps, and I would not doubt that it appears in JH's, too.
Still, I'm listing the main entry as "Not found", and putting a question mark
on the identity with N3051. Whatever the case, there is certainly only one
bright galaxy here, not two as JH has it.
The galaxy, by the way, is one of the "shell" galaxies, with coronae at
alternating distances on either side of the bright bar. NGC 474 is a dramatic
example; see Turnbull, Bridges, and Carter, MNRAS 307, 967, 1999 where the
shells are interpreted as the result of a merger of at least two galaxies.
=====
NGC 3047 is presumeably the brighter of a pair of galaxies just 1.1 arcminutes
south of HD 85384. Apparently co-discovered by Burnham and Hough, there is no
mention in their short note about a companion (nor about the star, for that
matter). The companion has had the suffix "A" added at sometime or other,
though I am choosing to call it simply "NGC 3047 comp".
=====
NGC 3048 appears to be a double interacting system in the background of an
undisturbed spiral. An earlier version of SDSS redshifts of the system
suggested that the bright spiral and one of two "in the background" are at the
same distance. However, the latest DR12 version (consulted in July 2015) has
these redshifts:
The brightest southwestern object has z = 0.02956 +- 0.00002
The faintest "middle" object has z = 0.03348 +- 0.00001
The northeastern object has z = 0.03349 +- 0.00001
These confirm the visual impression of an optical alignment.
Marth's single observation has only a position -- given, as usual, to only a
full minute of arc -- and the note "eF". While his observation is probably
dominated by the foreground spiral, I've nevertheless given directional
designations to all three.
=====
NGC 3050 = NGC 2979. Frank Muller found N3050 with the Leander McCormick
26-inch refractor. His description (m = 14.0, D = 0.6 arcmin, vlE at 200 deg,
gbMN) suggests that it would be hard to miss -- it's among the brighter of the
new nebulae found at Leander McCormick. However, there is nothing in Muller's
position.
NGC 2979, though, is 11m 15s preceding the place given by Muller. It matches
the description perfectly, and the declination is within an arcminute of that
given by Muller. If the RA is in error by 10 minutes of time, then the RA
difference falls into the range often seen in the Leander McCormick positions,
one to two minutes too far east.
I'm pretty well convinced that this is the correct identification, though
final proof is lacking. Unfortunately, there is no sketch, and Muller left us
no descriptions of field stars around the galaxy that would help identify it.
Still, the description and the Declination are right, and a digit error in the
RA is likely, so I'm going with this.
=====
NGC 3051 may also be NGC 3046, which see.
=====
NGC 3058s = IC 573 was found by Leavenworth at Leander McCormick. As usual,
the position is poor, though it was corrected by Howe. Leavenworth did note
the object as double or bi-nuclear; it is, of course, double with the southern
galaxy being the brighter. See IC 573 for more.
=====
NGC 3061 was found by WH on the night of 2 April 1801. The positions of all
fifteen nebulae in the sweep (No. 1096) are affected by large, systematic
errors. See NGC 3752 where I give the story of how it all came to be sorted
out, first by Dreyer; then by myself, Steve Gottlieb, and finally Wolfgang
Steinicke who has actually found the cause of the problem.
The field confused many observers trying to follow up WH's discoveries, not
least JH. See the "notngc" files under h 653 for more confusion in the area.
=====
NGC 3063 is the double star southwest of NGC 3065 and NGC 3066. Though N3063
was first seen by WH in 1802, he apparently described it only indirectly:
"F, pL, R; the last of three, the others are II 333 and II 334." The
position he gives is that of NGC 3066, and the description fits, too, so that
is probably the object he mistakenly thought was new. If so, he also mistook
the double star as one of his previous objects. His confusion was carried
over through the GC and d'A's catalogue into NGC, and eventually into Dreyer's
1912 reprinting of WH's papers. I actually prefer the numbering that he has
in the NGC itself as it more accurately reflects the history: NGC 3065 and
3066 are the true nebulae and are II 333 and II 334, respectively, while the
last object found is II 909 = NGC 3063.
This "last" object was not seen by JH, but was measured twice by d'A (his
position appears in the NGC). d'A also has six measures of the other two
objects, so he pinned down all three.
- - - - -
In August 2015, Courtney Seligman asked about the history of the discovery and
numbering of these objects, so I collected almost all of the information
available in the old papers. The only things missing here are d'A's extensive
Latin notes describing his observations.
Here are WH's notes from CH's fair copies of the sweeps:
3 April 1785, Sweep 390:
Two, S, pF, bM. The most north a very little larger and brighter than the
southern one; otherwise much alike; not far from being in the same meridian.
27 Ursa maj. f 20' 14" s 0o 2' RA 9h 45' 2" PD 16o 54'. (854, 855)
==> 10 02 04 +72 09.8 (J2000) Reduced wrt 27 UMa
10 02 43 +72 09.0 " Precessed from CH reduction
30 Sept 1802, Sweep 1112:
Three, the place is that of the last, which is F, pL, R. The sp one eF, vS
about 1' more south and, 1 F = 20" preceding. The np one pB stellar about
3' more north than that of which the place is taken, and, 15 [sic] F = 30"
preceding. 27 Ursa f 20' 3" s 0o 5' RA 9h 44' 51" PD 16o 57' (854, 855,
2508), RA & PD of the 1st 9h 44" [sic] 21' [sic]. 16o 54'. Of the 2nd
9h 44' 31". 16o 58'.
==> 10 01 58 +72 07.1 (J2000) Reduced wrt 27 UMa
sp 10 01 38 +72 06.1 " WH's estimated offset wrt measured neb.
np 10 01 28 +72 10.1 " Ditto
10 02 32 +72 06.1 (J2000) Precessed from CH reduction
10 02 12 +72 05.1 " Ditto
10 02 04 +72 09.1 " Ditto
Dreyer quotes the second of these in his 1912 edition of the Scientific Papers
(under II 909) and adds, "These three are NGC 3063 = II 333, 3065 = II 334,
and 3066 = II 909."
The NGC positions are
3063 09 49 27 17 12.4 ==> 10 01 43 +72 07.6 (J2000)
3065 09 49 40 17 09.4 ==> 10 01 56 +72 10.5 (J2000)
3066 09 49 45 17 12.3 ==> 10 02 00 +72 07.6 (J2000)
His NGC note for NGC 3063 reads
Probably II 909 is = II 334, which is pL according to d'A; but H must have
seen all three nebulae, as he says that II 909 is the last of the three.
Finally, in his 1912 MNRAS paper, Dreyer has
3063 is II 333
3065 is II 334
3066 is II 909
with no further comment.
JH (1833) has
654 II 333 09 46 01.4 17 00 57 vF, S, R, 10"; near * 11.12 m
==> 10 01 03.4 +72 10 41 (J2000)
655 II 334 09 46 16.4 17 03 48 F, R, 20", vglbM
==> 10 01 16.7 +72 07 48 (J2000)
both in Sweep 382 on 4 Nov 1831.
In CGH (1847), JH presents the "HON" list, including II 909 as Number 5 (his
position is for 1830):
5 II 909 09 47 09.0 17 03 55 F, pL, R; the last of 3, the others are
II 333 and 334. Follows 27 Ursae (G. 1563)
20m 3s, and is 0o 5' south of it.
Discovered Sept. 30, 1802.
==> 10 02 06.9 +72 07 34 (J2000)
For GC (1864), he has
1969 654 II 333 --- 09 48 42.7 17 09 25.2 pF, vS, R, bM; *11 nr
Position from 1 observation, 3 total observations by H and h
==> 10 01 01.3 +72 10 37 (J2000)
1971 655 II 334 --- 09 48 57.4 17 12 16.5 vF, vS, vglbM
Position from 1 observation, 3 total observations by H and h
==> 10 01 14.5 +72 07 44 (J2000)
1972 --- II 909 H.ON 5 09 49 50.5 17 12 24.7 F, pL, R; 3rd of 3
Position from 1 observation, 1 total observation by H
==> 10 02 05.7 +72 07 30 (J2000)
In the GC Supplement (1879), Dreyer has two notes:
1969, 1971 The minute of RA should be 49 (H and D'Arrest).
1972 = II 909. Not found by D'Arrest, unless it is a Nebula observed by him
in RA 9h 49m 27s (2 obs).
d'A (1864; with extensive Latin commentary as well):
H h 1861 J2000
II 909? --- 09 49 32.5 +72 47 21 n = 2 ==> 10 01 43.1 +72 07 35
II 333 654 09 49 45.0 +72 50 07 n = 6 ==> 10 01 56.0 +72 10 20
II 334 655 09 50 00.0 +72 47 34 n = 6 ==> 10 02 09.7 +72 07 45
=====
NGC 3065. See NGC 3063.
=====
NGC 3066. See NGC 3063.
=====
NGC 3069 = IC 580, which see.
=====
NGC 3070. See IC 580.
=====
NGC 3077 is one of the brighter satellites of M 81 = NGC 3031. Like M 82 =
NGC 3034, it is classified as an I0 galaxy -- and like M 82 shows very little
resolution into stars in spite of its being relatively nearby (contrast with
M 81 itself, NGC 2403, or even NGC 2976; all at about the same distance, 3.5
to 4 Mpc).
An additional peculiarity of this galaxy is its eccentric central bulge; the
nucleus is well off the center of the outer isophotes. Consequently, I've
given two positions in the table, one for the entire galaxy approximately
centered on those outer isophotes, while the second refers to the nearly
stellar red nucleus shown in the 2MASS and SDSS images.
=====
NGC 3080 is close to IC 585. Both were seen by Bigourdan who got the NGC
number on the correct object. I had some question about that as his position
is somewhat different from the NGC position.
The NGC position apparently comes from CH; it is based on a single observation
by WH who compared it to "the Georgian Planet" on 1 April 1794. After some
fussing about looking for an on-line ephemeris, Brian Skiff pointed me at
JPL's "Horizons". Jon Giorgini, one of Horizons maintainers, set me straight
on its use, so I was able to find that Uranus was at 09 57 30.0, +13 17 24
(B1950.0) on the night that WH used it as a comparison object. This position,
combined with WH's offsets (16 seconds preceding, 2 arcmin south) fell within
1.5 arcmin of NGC 3080, the brighter of the two galaxies.
Fortunately, not only did Bigourdan get it right, but he published a
correction to the NGC position that ended up in the IC2 Notes. Even that
position, however, is a bit off because he used the old BD position for his
comparison star. Once that is corrected, and proper motion taken into
account, his position lands within a few arcseconds of the modern ones.
=====
NGC 3081 = IC 2529, which see.
=====
NGC 3084 = IC 2528, which see.
=====
NGC 3088. Neither of the Herschels commented on the faint, edgewise
companion, so I've left the NGC number on the brighter galaxy. The suffixes
come, like many others, from the RNGC.
The galaxy has a faint companion on its east side that was seen by both R.J.
Mitchell and C.E. Burton with the Birr Castle reflector. See the "notngc"
files for more on the sightings.
=====
NGC 3097. I cannot find this one. Here are the original observations from
the Harvard Annals, Vol. 8, Part 1, page 62, 1882:
"Date GC RA (1860.0) Dec Remarks
1870 Mar.24 -- 09 54 19.6 +60 47 58.2 G.C. 1998 s f neb; p 45 deg
s 2'. [Place only approximate.]
1870 Mar.24 1998 09 54 36.7 +60 46 33.3 G.C. 1998: F; S; R; mbMN."
There are three things to note about these observations:
1) The position of the second (GC 1998 = NGC 3102) is from the GC.
2) The "p 45 deg s 2' " means that the first (N3097) is 2' away
from GC1998 at a position angle of 45 degrees. This is
inconsistent with the position which implies the object to
be northwest, not northeast, of N3102.
3) Both observations are credited to E. P. Austin, and there is
a note for N3097:
"Perhaps a nebulous star. It is half-way between G.C. 1998
and a star 11 magn."
The positions don't tell us anything we don't already know since they are
correctly transfered into NGC from GC and the Harvard list.
Since Austin was observing with a 15-inch telescope, I don't think that he
could have seen either of the faint stars Glen Deen measured during his
MicroSky project. The magnitude estimate given by Austin for the "star 11
magn" is rough since there is nothing that bright near the galaxy.
WH had this to say (N3102 = H III 916): "eF, vS, Stellar. Near a S st."
And JH: "F, vS, R, bM; a coarse D * nf points to it; has a * 11 30 [arcsec]
dist, pos 142.2 deg ." All of JH's stars are identifiable, and I think that
his star 11 must be the same one mentioned by WH and by Austin.
So, where does that leave N3097? My guess is that Austin has misidentified
another nebula as N3102, but I don't see it or its purported companion in the
area. A more thorough search may turn them up.
=====
NGC 3099. Like NGC 3088 (which see), neither Herschel noted this as a double
galaxy. It is, in fact, not -- the companion (itself a pair) is simply a
member of the same group. Holmberg was the first to note the companion; it is
Holmberg 160b, with NGC 3099 being Holmberg 160a.
=====
NGC 3100 = NGC 3103, which see.
=====
NGC 3102. See NGC 3097.
=====
NGC 3103 = NGC 3100. Swift's position -- which is empty -- is roughly midway
between NGC 3100 and NGC 3108, both found by JH. Swift notes a "coarse D* p";
it is actually following and a bit to the south of NGC 3100. Howe was the
first to make this identification in one of his MN articles; Dreyer has the
appropriate correction in the Notes to IC2.
It is just possible that N3103 is actually NGC 3108. The RAs are exactly a
minute of time different, and the declinations are within 0.1 arcmin.
However, N3108 has a pretty bright star about 1 arcmin to the south that Swift
probably would have mentioned (though JH didn't), and there are no double
stars nearby, neither preceding nor following.
=====
NGC 3105. JH has two observations of this in successive sweeps on 6 and 10
April 1834. In both sweeps, he notes "a train of large stars running out of
it, sp" and "a great train of sts 12 ... 13 m on the sp side." The chain of
stars is indeed there, but it looks to me like a random feature of the rich
Milky Way field. I've not included it in the position or diameter given in
the position table.
=====
NGC 3107. Given WH's estimated position -- "3/4 deg following, 1/2 deg north
[of the] Georgian planet," it's a wonder that this object was ever recovered.
However, WH also noted that the object is "3 arcmin north of a pL red star."
This pair of objects is unmistakeable enough that LdR had no trouble finding
it in spite of the poor position, and the confusion in the GC description
("L red star north 3 arcmin"). It must be said, however, that the GC
position, presumeably from CH's reduction of WH's observations, is remarkably
good, being only 6 arcmin south and 5 seconds east of the galaxy.
Dreyer picked the wrong star, however, as the "red" star near the nebula.
This led him to assign the wrong position to the nebula in his note in the
GC Supplement, in LdR's observations, and in the NGC. The correct star is
SAO 98932 (spectral type K2), not SAO 98925 (spectral type F5). Using the
SAO position for the correct star, and LdR's micrometric offsets, leads to a
position for the galaxy that is within an arcsecond of the GSC position.
=====
NGC 3108. See NGC 3103 = NGC 3100.
=====
NGC 3109. This large, nearby galaxy, just beyond the Local Group, was found
by JH in March of 1835. He took its position to be that of a superposed star
near the center of the brightest part of the galaxy. However, the bar is to
the east of the apparent center, and the approximate center of the bar is the
position I've taken to represent the galaxy.
=====
NGC 3110 = NGC 3122 = NGC 3518 (= MCG -01-26-014) and MCG -01-26-013 are an
interacting pair separated by 1.9 arcminutes; N3110 is the brighter of the
pair. N3122 is actually an observation of N3110, but WH confused his
comparison stars. Stephan's position is very close to the actual position of
the galaxy, but is about an arcmin off in declination. This is probably due
to the incorrect declination that he quotes for his comparison star (which is
not the same one that Herschel used).
Both Stephan (in his 1885 AN paper) and Dreyer (in MNRAS 73, 37, 1912) suggest
that the two NGC numbers refer to the same galaxy. Dreyer makes further
comments in his notes to WH's first catalogue of nebulae, (included in WH's
complete papers, edited by Dreyer in 1912) saying "Looked for but not found in
1787. It was the only object compared with `20 Sextantis,' but the star was in
reality B.1414. This gives for 1860 9h57m04s, 95d49m, in perfect agreement
with N3110 (Stephan XIII)." Stephan's position is actually 2 arcmin north of
this one, but the agreement is close enough to make the identification clear.
The two stars by the way, are SAO 137424 (20 Sex) and SAO 137400 (B.1414, from
Bode's catalogue used by CH in her reduction of WH's observations).
Coincidentally, there is a galaxy 2 arcmin south of WH's position. It is
the one that Jack Sulentic picked up for RNGC, but it is not in MCG. The RNGC
galaxy is at 10 03 47.1, -06 19 49 (GSC, B1950) and is much fainter. If WH
looked for it again in 1787 at roughly this location, then I'm not surprised
that he did not recover it.
The identity with NGC 3518 (which see), is yet another story.
=====
NGC 3114. JH gives three positions for this large cluster; I've included two
in the table. The other is probably a repeat of the second with a 20 second
error in the RA.
JH's first position refers to "... the centre of a bright equilateral
triangle". This is easy to identify, and JH's position is good. A second
position (10 02 40, -60 10.7 for J2000) for "The chief * 9 m ..." points at
only faint stars. As I said above, I think that it is 20 seconds in error and
actually refers to the same star as his third position for "The chief * 8 m
...". JH had a different suggestion that he added when he was later preparing
CGH for publication: "As both this and the last observation are distinctly
written and correctly reduced, no doubt they belong to two distinct and nearly
equal stars on the same parallel." As we've seen, though, there is only one
bright star, HD 87436 that he probably picked up both times.
The position, and indeed the composition, of the cluster is uncertain. I make
it over half a degree in diameter, and centered more than 30 seconds of time
west of either Brian Skiff's estimate or ESO's position. The cluster is more
or less outlined -- as I see it in a 1 degree DSS image -- by a group of 6-8
stars that closely resemble the "home plate" of bright stars in the
constellation Auriga. I'm sure that a study of the area has been done, and I
would guess that there is indeed a real cluster here. But to my eye, it looks
scattered and a bit "diluted" by the rich Milky Way background.
=====
NGC 3119 is perhaps the same galaxy as NGC 3121. There is no doubt about the
identification of N3121. This was found by William Lassell in 1848 (see AN
635; my thanks to Courtney Seligman for sending along a copy of the original
paper) with one of his smaller telescopes. It was reobserved by Arthur
Auwers, who noted the 9th magnitude star 4 arcmin north and 14-15 seconds of
time preceding. The position listed by Auwers (1862) is very good.
N3119 was found by Albert Marth in 1863 with Lassell's 48-inch reflector. He
describes it only as "vF." His position, from one observation, falls about
an arcmin southwest of NGC 3121; it is also 2.4 arcmin north of the galaxy
that RNGC chose as N3119: CGCG 093-045. This is considerably fainter and
smaller than N3121. Wolfgang also favors CGCG 093-045 and reports that it is
visible in his 50-cm reflector as a slightly non-stellar patch.
So, Marth almost certainly could have seen CGCG 093-045. However, since his
position is closer to N3121, and since that galaxy is the brightest in the
area, I think it more likely that Marth's observation refers to it. Wolfgang
and RNGC could be right, of course -- but then, why didn't Marth mention
reobserving the galaxy that his mentor had found 15 years before? Would he
even know about it? We don't have answers to these questions.
=====
NGC 3121. See NGC 3119.
=====
NGC 3122 = NGC 3110 = NGC 3518 (both of which see).
=====
NGC 3123. Here is my original note on this object:
[This] may be one of the stars, or the double star, that I've listed in the
table. There are no nebulae in the area that Sidney Coolidge could have
seen with the 15-inch refractor at Harvard.
His position is noted as having a range of 4 seconds of time in RA, and 2
arcmin in Dec. All of the objects I've noted as possibilities are more or
less within those ranges, though the star that I've noted with a single
question mark is closest. It has two faint companions to the south (one
looks like a galaxy) that may have added a bit of fuzziness to the image.
I should note, however, that many of the "nebulae" found during the Harvard
refractor's first decade are actually single stars, presumeably found on
nights of less than good seeing. This may be another of those.
However, Steve Gottlieb wrote in March 2015 that he has examined the Harvard
Zones where the object was first published. He has found that the only object
in Zone 117 which has a note even suggesting nebulosity is number 47 with the
remark "Has a perceptible disc?" The position of the object is given as
10 10 58.91, +00 44 39.3 for 1859.0; this precesses to 10 18 12.83,
+00 02 26.6 for J2000. Given the proper motion of -37.1 mas/yr in RA and -6.1
mas/yr in Dec, the position for J2000 (10 18 12.5, +00 02 26) corresponds well
enough that for UCAC4 451-050216 (10 18 11.89, +00 02 24.7).
Thus, the Harvard star is pinned down. But where does Bond (in AN 1453) find
the published position 09h 59m 48s +-4s, +00d 45' +-2' for 1859? The
declination is correct if the star is indeed number 117-47, but the RA is
wrong (there is nothing in the Harvard Zones at the position with that RA). I
am also curious about the errors that Bond assigns to the position -- the
typical differences in the overlap areas between measurements in the different
Harvard Zones is around 2-3 arcseconds, not the 2 arcminutes that Bond gives.
So, there are still some problems here. Still, I think that Steve has found
the correct object -- star 47 in Zone 117 -- so give that in the main table,
though with colons.
=====
NGC 3125 appears to be a close double galaxy, though may be single with at
least two -- possibly more -- bright knots. The nominal nucleus is coincident
with the western component, while the eastern appears to be more diffuse.
I've given positions for both of the objects -- whatever they are -- and list
the mean for "NGC 3125" itself.
After I wrote that, Courtney Seligman did a quick literature search for this
galaxy and has found three papers that suggest that the bright knots are
actually young star clusters with many supergiant stars, including Wolf-Rayet
stars (see Wofford et al ApJ 781, 122, 2014; Hadfield and Crowther MNRAS 368,
1822, 2006; and Chandar et al ApJ 604, 153, 2004). Thus, these clusters are
similar to well-known superassociations like NGC 2070 (30 Doradus) in the LMC
and NGC 604 in M 33.
=====
NGC 3129 is a double star seen by both WH and JH. WH's position, adopted by
JH, is good, and both descriptions are appropriate. It appears, however, that
LdR must have seen it as a star or a double star, as he could not find any
nebulosity at WH's position on three different nights. Dreyer has a note in
NGC to that effect.
=====
NGC 3130. There is nothing wrong with the position of the galaxy in the NGC,
but the note in the description "* 5 sf" needs to read "* 5 np". JH has this
in his 1833 catalogue: "... follows 31 Leonis 16s.5, and is 1' 40" s of it";
this is correct. But the GC reads, "... 31 Leon sf 100" ".
I take all this to mean that both JH and Dreyer were moving quickly through
their cataloguing chores -- in this case, quickly enough to get the
orientation of the star and the galaxy confused.
I can empathize.
=====
NGC 3134 is David Todd's number 21a, found during his search for "the trans-
Neptunian planet." It can be more or less confidently identified with Todd's
sketches, and his measurement of the separation between the galaxy and a star
("b" in his sketch; it is UCAC 512-048943 at 10 12 57.7 +12 22 50; J2000):
28.4 seconds of time. The only remaining problem is that another "star" in
the sketch just northeast of "b" is not on the sky; could it have been an
asteroid?
See NGC 3604 for more on Todd's observations.
=====
NGC 3140 and NGC 3141. The field exactly matches the sketch that Leavenworth
made, and his descriptions also match, down to the bright nucleus in the
brighter galaxy. His original descriptions make it clear that the galaxy that
got the smaller NGC number is actually the brighter, northeastern member of
the pair.
Here are his data from AJ 7, 9, 1886:
No. RA (1890) Dec Mag Size Form Condensation [NGC]
166 10 04 -16 06 15.5 0.5' R sbMN [3140]
167 10 04 -16 06 16.0 0.3 R --- [3141]
Dreyer has added the notes "1st of 2" and "2nd of 2." I suspect that he
thought that the larger and brighter galaxy was the preceding since it was
listed first in the table. That turns out to be wrong, unfortunately, so
the NGC numbers are reversed from the right ascensions.
=====
NGC 3141. See NGC 3140.
=====
NGC 3142. Dreyer squeezes a note "(d'A, PD 43'.3, 1 obs)" into the
description of this in NGC. JH's minutes of polar distance are "47.9" for
1860.0, and he is correct. d'A's position is about 4.3 arcminutes too far
north which makes it identical to the declination of 17 Sextanis. The star is
very close to having the same RA as the galaxy, too. This makes it likely
that d'A mistakenly inserted the position of the star -- perhaps it was his
comparison star? -- rather than that of the galaxy, into his table.
=====
NGC 3144 = NGC 3174. D'A found NGC 3144 in the late 1850s and measured its
place pretty accurately. NGC 3174 is from WH's 2 April 1801 sweep 1096 which
was affected by a large, systematic error of some sort. See NGC 3752 for more
on this sweep, and how we sorted it out.
=====
NGC 3148 = GM UMa = HD 88512 is only a star. JH's description reads "A star
7m has a photosphere 2 or 3 arcmin diam. Sky perfectly clear; glass quite
clean; windy. Another * of same mag viewed presently after has no
photosphere." There is certainly no bright nebulosity that large around the
star, and it is not a double or multiple star, either. Its only "peculiarity"
is that it is an eclipsing variable.
JH has a couple of other stars which he suspected of nebulosity, too, which
show none today. These must be illusions of some sort, though difficult to
account for. Perhaps they were caused by very thin, evanescent clouds or fog?
=====
NGC 3153, discovered by WH, is also David Todd's number (20b), found during
his search for "the trans-Neptunian planet." See NGC 3604 for more.
=====
NGC 3155 = NGC 3194. NGC 3155 was found by JH and later remeasured by d'A.
Their position, used in the NGC, is quite accurate. NGC 3194 is from WH's
sweep 1096 of 2 April 1801; all the nebulae in that sweep have large,
systematic position problems. See NGC 3752 for more.
=====
NGC 3157 = IC 2555, which see.
=====
NGC 3162 = NGC 3575, which see.
=====
NGC 3167 is almost certainly NGC 2789 with a 1 hour error in the RA and a 1
arcminute error in the declination. The "* 11 preceding 9.5 seconds, slightly
north" that d'A notes in his description is just where he puts it in
relation to the galaxy. There are few other objects in d'A's list with big
digit errors (NGC 3575 is an example). D'A also notes that it could be a
small cluster, but the night (1 May 1862) was bad, and he never reobserved the
object.
=====
NGC 3170 is a double star. JH's position is just an arcminute south-
southwest, and the double is very much like the several others that he mistook
as nebulae. Interestingly, the double is also Reiz 248. I do not have Reiz's
catalogue available, but would suspect that he picked up the object from the
NGC. Reiz, like Holmberg, worked from Bruce 24-inch plates, so mistook many
faint stars near the plate limit as galaxies.
=====
NGC 3174 = NGC 3144, which see.
=====
NGC 3176 may possibly be the galaxy a degree south and 23 seconds preceding
Ormond Stone's position. However, the object (ESO 567-G029) is about half the
size that Stone estimated and nearly round. Stone's description in full is
"Mag = 16.0, Diameter = 0.8 arcmin, iR, neb?" from a single observation. As
usual in the first list of Leander McCormick nebulae, the position is given
only to a full minute of time in RA and one arcmin in Dec.
There is no sketch, and the galaxies near Stone's position that he might
possibly have seen all have stars nearby that are bright enough that he would
have mentioned them as neighbors.
Consequently, the identification with the ESO galaxy is tentative at best.
=====
NGC 3180 is part of the northwestern arm of NGC 3184. For a long time, I
thought that the number applied only to an HII region or star cloud in the
northern part of the arm. But there is a sketch in LdR's 1861 monograph that
shows the spiral arm connecting NGC 3180 and NGC 3181. It has both as patches
extended along the arm, with NGC 3180 at the northern end and NGC 3181 at the
southern. I've left the positions of the HII region -- actually a line of
three knots, the southern perhaps a star -- and the star cloud in the table to
differentiate them from the arm itself.
=====
NGC 3181 is the brightest HII region, and the area of the spiral arm around
it, in NGC 3184. See NGC 3180.
=====
NGC 3183 = NGC 3218. NGC 3183, found by d'A, has an accurate position given
in the NGC. NGC 3218, found by WH on 2 April 1801, does not; all the galaxies
found that night have large, systematic position errors. See NGC 3752 for
more.
=====
NGC 3184. See NGC 3180.
=====
NGC 3185. See NGC 3189.
=====
NGC 3186 is perhaps the northeastern component of CGCG 036-074. There is
nothing at Marth's position, and the CGCG galaxy is 1 minute 30 seconds west
and 6 arcmin south. There are, however, "sev F sts near" as noted in the NGC
-- but not by Marth; more below -- about half a dozen within 5 arcmin of the
galaxy. The southwestern component of the CGCG galaxy, by the way, is itself
a double galaxy with a superposed star.
The nearer, though fainter, candidate galaxy, CGCG 036-085 (20 seconds east, 5
arcmin south) has only three nearby stars that Marth may have seen, so may or
may not match the NGC description, depending on one's notion of "several".
But -- the NGC note about the nearby faint stars is not in Marth's original
description. Dreyer had added it by the time he published the GC Supplement
in 1878, but I have not been able to trace the source of the note. It is not
in LdR's observations, and Dreyer has no reference in the Supplement. Given
that uncertainty, I'm reluctant to discount either galaxy.
Nor is there a systematic offset in Marth's positions for the other 25 objects
he credits to the same date, 1865.23. NGC 3186 seems to be the only object
from that date with a large offset from Marth's position.
All in all, not a very satisfactory identity.
=====
NGC 3187. The position I've adopted for this famous, distorted spiral is that
of the faint, stellar nucleus. There is a possibility, worth checking, that
the nucleus is actually a superposed star. See also NGC 3189.
=====
NGC 3189 is the southwestern side of NGC 3190, a nearly edgewise galaxy split
by a prominent dark lane. The galaxy itself is the brightest in a famous
group also including NGC 3185, NGC 3187, and NGC 3193.
=====
NGC 3190. See NGC 3189.
=====
NGC 3191 = NGC 3192, which see.
=====
NGC 3192 = NGC 3191. WH's NPD is -9 arcmin in error, close enough to 10 to
make this pretty clearly a digit mistake in reduction or copying. WH's
description, "eF, vS. Perhaps a patch of small stars" is also appropriate
for NGC 3191 which has several OX knots in it.
The identity was first suggested by JH, and was later taken up by Dreyer.
=====
NGC 3193. See NGC 3189.
=====
NGC 3194 = NGC 3155, which see.
=====
NGC 3197 was found by WH on 2 April 1801. All fifteen objects he found this
night are more or less affected by large position errors. See NGC 3752 for
more on the sweep (No. 1096).
=====
NGC 3199. Glen Cozens has found that this is Dunlop 332 with a one-degree
error in Dunlop's south polar distance (he put it 1 degree too far north).
JH rediscovered the object independently a decade later. He had the north
polar distance correct, so did not notice the identity with Dunlop's object.
The NGC object is the western part of a large, annular, HII region. I've
given an approximate center for that, as well as JH's three slightly different
positions for various stars within the 12' x 4' crescent that JH saw. I've
also given an approximate center for the entire 23' x 20' annulus. ESO did
the same thing, but estimated the center to be about 10 seconds of time west
of where I've put it. This may be because Andris Lauberts was looking at a
blue plate, while I'm restricted to the DSS2 red image. In any case, the
object is far enough south, and large enough, that the 10 second difference is
irrelevant to its identification and appreciation.
=====
NGC 3210 is a star about an arcminute west-northwest of NGC 3212. (I had
called it a double star earlier, but no longer see the very close companion
that led to that conclusion.) WH's description is appropriate, and his
position (for three objects; the third is NGC 3215) is good. There is another
slightly fainter star about 23 arcsec preceding NGC 3210; is it possible
that WH glimpsed this, too? If so, it may have added to the illusion of
nebulosity.
=====
NGC 3212. See NGC 3210.
=====
NGC 3215. See NGC 3210.
=====
NGC 3217 = IC 606. The IC position, from Javelle, is good, but the NGC
position, from David Todd's paper chronicling his search for "the
trans-Neptunian planet", is over two minutes of time off. Fortunately, Todd
has left us a sketch in his article, so we can positively identify the galaxy
he saw. (See NGC 3604 for more about Todd's objects.)
Because he was searching for a new planet, Todd was concerned about observing
possible motion across the sky. His note for this object (his number 29) is
almost totally concerned about its motion, yet helps us to identify the
galaxy, too. Here, for those interested, is the complete note from Todd's
second observation ("a" is the object in question, "c" is a nearby star):
"1878 Mar. 4.6, delta alpha (ac) = 5.2s +- 0.1s [the separation on the DSS
is 5.5 seconds]. I feel quite sure that 'a' has not moved: the delta
alpha (7.0s) [from the discovery night 28.5 Feb 1878] was put down from
memory on March 2, without much hope of its being right. But, judging from
the configuration, I say that 'a' has not moved appreciably."
=====
NGC 3218 = NGC 3183, which see.
=====
NGC 3220 = IC 604, which see.
=====
NGC 3223 = IC 2571, which see.
=====
NGC 3228. JH's position is crude and marked uncertain. But the group of
stars is so striking and so perfectly described by JH, "A group of 9 L, and a
few sc small stars", that there is no mistaking the correct object.
=====
NGC 3229 is a triple star. It is very close to Coolidge's position, and is
similar to several other asterisms discovered at Harvard in the early 1850's.
The hours of RA (20) in the NGC is a typo there, not in the original paper
in AN.
=====
NGC 3231 may be a sparce cluster, but is more likely a random collection of
stars. JH's description is exact: "A cluster of 20 stars more or less, 10,
11, and 12 m, scattered over a space 10' diam. A star 7 m s." This shows
that it is considerably more than Brian Skiff's "2.5' diamond-shaped *ism of
seven *s, m11-14."
JH's position is for the brightest star on the western edge of the group. The
center is about 30 seconds on east.
Also see NGC 4512.
=====
NGC 3234 is almost certainly = NGC 3235. JH's position is exactly 1 degree
north, and his description fits. Dreyer was the first to suggest the identity
and his NGC note documents his idea. Unfortunately, his note in IC1 confuses
the issue: "3234 is not = 3235; both seen by Denning." While I've not seen
Denning's observation (it is not in his short paper about the circumpolar
nebulae where he announces the discovery of several IC objects), I suspect
that he must have picked up the two objects that d'A found: N3232 and N3234.
There is certainly nothing nebulous at the nominal position for N3234, and the
exact 1 degree error in JH's position argues convincingly for Dreyer's first
interpretation.
=====
NGC 3235 = NGC 3234, which see.
=====
NGC 3239 is a large, nearby, low-surface-brightness, late-type spiral. It is
coincidentally seen on the sky around a 9th magnitude star noted by both WH
and JH (in three different sweeps). I've given the position of the star in
the table as well as that of the galaxy itself.
The galaxy's position is relatively difficult to determine. There is no
nucleus, and the bar is patchy with knots and resolved supergiants. However,
the SDSS image shows a faint peachish haze in the brightest part of the bar
toward the eastern end of the galaxy. This is what is left of the "nuclear
bulge" in a galaxy of this type. I've estimated the position of this bulge on
the DSSR2 image, and have adopted that as the position of the galaxy. There
is a bright complex of HII regions south-southeast of the center of the bar,
and I give a position for that as well.
Finally, a neighboring galaxy, CGCG 094-042, was glimpsed by both Mitchell and
Hunter with LdR's Birr Castle "Leviathan." See the short story on that in the
"notngc" files.
=====
NGC 3247. JH's position is approximate. Though he has three observations of
this, only one -- and possibly not even that -- was made on the meridian. The
only thing matching his descriptions "Stars involved in evident nebula," "A
decidedly nebulous group," and "There is a nebulous appearance, which merits
re-examination," is the HII region I've listed in the table with its attached
cluster. Brian Skiff identifies this cluster as "Westerlund 1", but Brent
Archinal in "Star Clusters" corrects this to "Westerlund 2".
Brent also notes that Collinder 220 is often mistakenly called "N3247", as it
is in ESO -- and indeed was here until I stumbled across the little cluster in
the 2MASS Extended Source Catalog. The nebula shows nicely in the DSS2 red
image where it is about 6 x 4 arcmin across.
The correct identification was first made by Stewart on a Harvard plate (and
included by Dreyer as an IC2 Note), but his position is about 3 arcmin
southwest of the center of the object.
=====
NGC 3251 = IC 2579. D'Arrest's RA is just 1 minute of time off, an error
first suggested by Dreyer in a note to IC2, as well as in the description for
IC 2579. The galaxy is positively identified by d'A's note about the three
stars to the southwest.
There is no problem with Javelle's observation for the IC entry -- it is
accurate.
=====
NGC 3252 has a two minute error in its RA and a 4 arcmin error in its Dec.
But it is far enough north that the RA error amounts to just over 8 arcmin, so
there is no mistaking the bright galaxy that WH found.
=====
NGC 3256. While there is no doubt about the identification of this well-known
southern interacting galaxy, the optical image shows a chaotic central bulge
with several bright points that could be the nucleus. However, the 2MASS
Extended Source Catalog (infrared) and the XMM-Newton Serentipitous Source
Catalogue (X-ray) positions agree to within a tenth of an arcsecond. Both are
close to my own measurement on the 2MASS J-band image, so probably pinpoint
the nucleus of the galaxy.
=====
NGC 3257. See NGC 3260.
=====
NGC 3258. See NGC 3260.
=====
NGC 3260. Discovered by JH on 2 May 1834, he observed it in three additional
sweeps. Even though it is in a compact group with NGC 3257 and NGC 3258, the
relative positions within each sweep are accurate, and the mean positions
given in CGH, GC, and NGC are good enough for positive identifications.
An interesting sidelight on this galaxy came from Lewis Swift who found it on
30 December 1897. I find the story, brought to my attention by Gary Kronk in
May 2017, to be a fascinating one, and illustrative of Swift's interests,
publishing methods, and observational accuracy.
He published the observation in four different places (AJ 18, 135; MNRAS 58,
331; Pop. Astron. 6, 18; and AN 147, 209 = AN 3517; all 1898), the first three
carrying the following note (this is the AJ version):
Here are two nebulas [the second is NGC 3333, which see] singularly placed,
whose descriptions, as will be seen, are identical in every particular. I
ran across a very faint nebula which I found to be NGC 3267 [actually NGC
3258]. Near following was an exceedingly faint and very close double star,
which, with a power 132, looked as if the north one was an exceedingly small
nebula of unimagined faintness. With a power of 200, my suspicion that it
was not a star was confirmed. In a few minutes, I ran across another, which
in every particular was exactly like it, both being north of its companion
star, and the same distance apart, about 4", and of the same size and
faintness. But for the excellent seeing and superiority of my periscopic
eye-piece [sic] for revealing faint nebulas, they would have escaped
detection.
In the MNRAS version, "nebulas" becomes "nebulae" and Swift adds the following
sentence:
If they are as distant as their companion stars, they must vastly exceed in
volume the orbit of Neptune, and yet are self-luminous.
In the Popular Astronomy version, this final sentence becomes
These minute objects if as distant as their companion stars must in volume
vastly exceed the orbit of Neptune and yet are self luminous [sic].
In 1897, Neptune of course was the planet with the largest known orbit, so
would be a natural comparison object for any other celestial object thought to
be large. The Popular Astronomy version also omits the sentence concerning
the seeing and the periscopic eyepiece.
Almost all of this is omitted in the combined AN list where the note is
combined with other objects:
Nos. 115 [NGC 3333], 137 [IC 3290], 159 [IC 4299], 163 [IC 4350], 172 [IC
4453]. These appear at first glance like double stars 6" or 8" apart, like
Nos. 6 [IC 1589] and 27 [IC 1740], but while each component of the latter
are nebulous, only one of the former is a nebula.
Here are Swift's observations from each of the four papers, leading off with
the AJ:
Date
No. 1897 RA (1900) Dec Description
23 [Dec.] 30 10 24 30 -35 3 15 eeeF, eeS, R, eF st in contact s, p of 2
24 30 10 35 12 -35 31 35 eeeF, eeS, R, eF st in contact s, f of 2
Next, from the Monthly Notices:
23 [Dec.] 30 10 24 30 -35 3 15 eeeF, eeS, R, eF, * in contact S, p of 2.
24 30 10 35 12 -35 31 35 eeeF, eeS, R, eF, * in contact S, f of 2.
Now, from Popular Astronomy:
23 [Dec.] 30 10 24 30 -35 3 15 eeeF. eeS. R. eF* in contact S. f of 2. Note.
24 " 30 10 35 12 -35 31 35 eeeF. eeS. R. eF* in contact S. f of 2. Note.
Finally, from the combined AN 3517 list:
108 [Dec.] 30 10 24 30 -35 3.3 eeeF; eeS; R; eF * in contact s; sp of 3267
115 " 30 10 35 12 -35 31.6 eeeF; eeS; R; eF * in contact; sf of 2. Note
These excerpts for the two galaxies show quite well the minor differences that
exist in Swift's multiply-published lists. The style of the entries changes
from journal to journal (perhaps an editorial touch?), as does the relatively
mysterious notation "p of 2"/"f of 2". Which two objects is Swift thinking of
here? If these two particular objects, they are over two degrees apart,
hardly close enough to be worth mentioning. The sudden appearance of NGC 3267
in the AN description is easily explained by the omission of the more
extensive note in the earlier three papers. And Swift's object is indeed "sp"
(southwest) of NGC 3267 (by 18.5 arcminutes). But if this is mistake for NGC
3258 as I think it must be, then it should read "nf of 3258". Also worth
mentioning here is that the dates and positions are the same -- this is not
always true for Swift's objects found at Lowe.
So, here is a close look at Swift's working methods in one of his more easily
resolved cases. He has given us good positions and notes that help identify
the objects he saw. Even if the relative position comments ("p of 2", "sf of
2", etc.) are somewhat garbled, the gist of each observation nevertheless
comes through. Swift was a typical astronomer of his day, interested in
virtually anything that appeared in the sky. If he chose to focus on comets
and nebulae, he was as much driven by curiosity about these fuzzy apparitions
as we are today.
=====
NGC 3261. See NGC 3366.
=====
NGC 3267. See NGC 3260 and NGC 3271.
=====
NGC 3268. See NGC 3271.
=====
NGC 3269. See NGC 3271.
=====
NGC 3271 = IC 2585 has an error of 20 seconds in its NGC RA. The NGC identity
is not in doubt as it is one of the four bright galaxies in the area, and JH
has four nebulae in a group listed in his CGH Observations.
However, his observations are a bit confused since he mentions a fifth nebula
"... more remote and brighter ..." in his description for NGC 3268. Since
there are only the four entries (corresponding to N3267, N3268, N3269, as well
as N3271) in his CGH list, and since he mentions only four nebulae appearing
in the diagram (not published) made during Sweep 571, we now have no way of
knowing where he saw his fifth nebula.
Aside from the 20 second RA error, the positions he adopted from the diagram
for the CGH list and the GC (copied into the NGC, of course) are good enough
to unambiguously identify his four listed objects, so it is unlikely that any
of them are the fifth object.
It's also clear that Stewart picked up the galaxy (on a Bruce plate taken at
Arequipa) because of the RA error. Thus, it also carries the IC number.
However, Stewart makes no mention of any of the NGC objects in the group.
This is particularly puzzling since he obviously thought that N3271 was
missing. Still, his position for it is good, and the identity with IC 2585 is
secure.
=====
NGC 3272 is a double star. Schultz's position is within an arcsecond of the
modern position, and his complete description (F, vS, iR, stellar, r, m=12-13)
fits perfectly. He also has a note that reads, "Nova VI an insignificant
object; p h721 [= NGC 3277] about 68 seconds and 160 arcsec south; ..." Those
distances also exactly point to the double.
=====
NGC 3277. See NGC 3272.
=====
NGC 3279 = IC 622 is another of David Todd's nebular discoveries (No. 30) dug
out while searching for a "trans-Neptunian" planet. Todd has left us sketches
of all of his objects (see NGC 3604 for more), so the poor positions that he
also left can at least be used to get us into the right area of the sky.
In this case, Lewis Swift picked up the galaxy a dozen years after Todd (on
4.5 March 1878, Swift on 29 Jan 1890). Swift's position, for once, is not too
far off, though he notes a "9m * s" -- that star is actually north, and is the
one Todd labels "b" on his sketch.
=====
NGC 3280 = NGC 3295 is a triple galaxy discovered independently by both
Ainslie Common with his 36-inch reflector (this telescope eventually found its
way to Lick Observatory where it was called the "Crossley Reflector" after its
purchaser, Edward Crossley of Halifax, England). Though Common noted only two
nebulae in his object, Francis Leavenworth found and sketched all three with
the Leander McCormick refractor. He also found (on the same night, 26 Feb
1886) NGC 3296 and 3297. The identities of these two are not quite as clear
from his sketches, so having them near in both time and space helps us to
identify them with certainty.
Unfortunately, neither Common's nor Leavenworth's positions are very good.
(Leavenworth's is, as usual for the LM nebulae, too far east, this time by
2m 40s. His declination, however, is less than an arcminute off. Common's
RA is 20 seconds of time off, and his declination 8 arcmin too far north.)
This led to the brightest galaxy being rediscovered by Stephane Javelle and
included in IC1 as IC 617, which see.
Herbert Howe finally suggested that N3280 and N3295 were the same object, but
did not notice the identity with IC 617.
=====
NGC 3283 is ESO 263-G48. JH puts a plus-minus sign on the RA and notes "RA
coarsely taken by an auxillary star." In addition to the uncertain RA is the
GC (and NGC) NPD -- it is 10 arcmin too small. This must be an error in
transcribing/precessing the CGH position into the GC.
Once these are taken into account, ESO 263-G48 is the obvious candidate.
=====
NGC 3284 = NGC 3286 is the brighter of two galaxies found by WH in April of
1793 (the fainter is NGC 3288). The number N3284 applies to H III 912 seen
on the 8th of April, while N3286 belongs to III 917, found the next night
along with N3288 = III 918. The GC/NGC position of N3284 is 10 seconds too
small (presumeably a reduction or transcription error) compared to my
re-reduction of WH's position, so Dreyer did not comment on the possible
identity until he prepared WH's papers for their 1912 publication. There he
also notes that Bigourdan did not find N3284.
A few other objects found the same night by WH show no systematic offset in
their re-reduced positions, so the declination offset implied by the identity
with N3286 is unique to III 912. The explanation adopted by RNGC (N3284 is a
star) is considerably less likely.
=====
NGC 3286 = NGC 3284, which see.
=====
NGC 3288. See NGC 3284.
=====
NGC 3291 is a star exactly at Bigourdan's position. Though he could not find
it on a second night, his two measurements on the first are accurate. In
addition, his comment "NGC 3294 is toward PA = 35 deg, d = 4.5 arcmin" is
also correct. The identity is thus certain.
=====
NGC 3294. See NGC 3291.
=====
NGC 3295 = NGC 3280, which see. IC 617 is the brightest of this triple
system; see that also.
=====
NGC 3296 = IC 618. As with NGC 3295 = NGC 3280 (which see), Leavenworth's RA
is nearly 3 minutes of time too far east. And as with N3295, Howe identified
the correct galaxy, but did not notice the IC1 number, from Javelle's first
list of new nebulae.
Leavenworth left us a sketch of the galaxy, but the orientation is not sure,
so I'm depending on the fact that the discovery date as well as the
(incorrect) RA is the same as for N3295 and N3297. Leavenworth's declination
is close, however, and his description is appropriate for the galaxy.
=====
NGC 3297. This shares with NGC 3295 = NGC 3280 (which see), and NGC 3296 =
IC 618 (also which see), a large error in RA. Leavenworth found it on the
same night as the other two, however, so we can be pretty sure of the identity
even if the orientation of his sketch is not quite sure. As with the other
two, his declination and description is good.
Herbert Howe looked for, but did not see this galaxy with any certainty. He
says (in a note for IC 2593 which he found nearby), "On 1899 April 10 I
measured the places of 3295 and 3296. I could only suspect 3297."
Nevertheless, the galaxy is there.
=====
NGC 3301 = NGC 3760, which see.
=====
NGC 3308. See NGC 5298.
=====
NGC 3309. See NGC 5298.
=====
NGC 3311. See NGC 5298.
=====
NGC 3312 = IC 629, which see.
=====
NGC 3314 is two superposed spirals, one with PA = 140 deg, the second somewhat
smaller and fainter with PA = 40 deg. The nuclei are nearly coincident,
making it very difficult to provide separate positions for them. I've tried,
nevertheless, but I wouldn't put much weight on my attempts. In any case, you
can find them well enough from the position for the NGC number.
There is a spectacular image of the pair in the Hubble Heritage gallery (see
http://heritage.stsci.edu/2012/29/big.html) that shows clearly what we're up
against as we try to detangle the two objects.
Also see See NGC 3315, where this plays a role in the identification of that
object.
=====
NGC 3315. My original thought that this might just be a duplicate
observation of NGC 3314 is unlikely since the discoverer E.P. Austin has an
observation of NGC 3314 on the same night. Also, Austin's description refers
to a "star np neb 1 arcmin." While there is a star 1 arcmin northwest of
NGC 3314, it is actually fainter than another star much nearer the pair, also
on the north side. So, I now support the idea that there is a 30 arcmin error
in Austin's declination (which was not micrometrically measured as some of his
were), and that NGC 3315 is actually ESO 501-G48. RC3, therefore, is most
likely correct. Still, colons go on the identification.
=====
NGC 3317 is probably the triple star I've noted in the position table. Found
24 March 1870, probably during the same observing session as NGC 3314 and 3315
(both of which see), E. P. Austin gave this only an approximate position (10h
31m, -26d 48m for 1860). This is the only object five arcminutes north of
NGC 3316 that Austin might have reasonably seen. There are galaxies in the
area, but they are much too faint to have been picked up with Harvard 15-inch
refractor.
=====
NGC 3321 = NGC 3322. This was first found by Ainslie Common with his 36-inch
reflector that finally ended up at Lick Observatory (where it was known as the
"Crossley Reflector" after Edward Crossley, the intermediate owner who was
persuaded to give it to Lick. The story is told in the Introduction to Volume
VIII of the Lick Publications, the volume of beautifully-reproduced
photographs taken with that telescope by James Keeler). Common claims in his
short paper in Copernicus that this -- and about 30 other new nebulae -- were
found in 1880. He estimated the position; his RA is OK, but his Dec is off.
Seven years later, on Jan 3, Francis Leavenworth came across the galaxy with
the 26-inch refractor at Leander McCormick. Like many of the positions of the
objects found there, the RA is off, but the Dec is pretty good. Both Common
and Leavenworth, by the way, provided adequate descriptions of the galaxy,
noting the star to the northwest. Leavenworth seems to have confused east and
west, though, at least as far as the position angle of the galaxy is
concerned. He recorded it as 160 degrees, while the actual angle is close to
20 degrees, a simple quadrant error.
Herbert Howe was the first to note the probable identity of the objects,
making NGC 3322 (the entry with Common's name on it) "not seen on two nights."
It's pretty clear, though, there being no other galaxy as bright within 30
arcmin, that both Common and Leavenworth found the same object.
=====
NGC 3322 = NGC 3321, which see.
=====
NGC 3324. On Brian Skiff's advice, I've taken the position to be JH's double
star (HJ 4338 = HD 92206; JH makes the separation three arcsec, and the
position angle 91.5 degrees on 1 April 1834). JH made it clear in his
description of the nebula that it extended at least as far south as the
brighter star (HD 92207) on the southern edge. But this splendid object
is so large that no one will miss it with any of the positions I quote in the
table.
For the record, the two lobes of the nebula (presumeably as seen on the
Harvard plates; see IC 2599 for more) are centered at 10 37 13, -58 36.6
(northern lobe) and 10 37 29, -58 41.9 (southern; both J2000 from the DSS1V
image via SkyView). There is also a cluster of young stars involved in the
nebulosity; see Juan Claria's paper in A&AS 27, 145, 1977 for more on that (I
thank Brian for the reference).
Also see IC 2599, the southern part of the NGC object, for more on this object
and the bright stars in it.
=====
NGC 3328 is probably a pair of stars near Peters's position. Spitaler's
position given in a note in IC1, is for another pair of stars about 5 arcmin
southwest. Both observers saw and measured NGC 3332 (which see) when they
worked on N3328, and both have good positions for that. Since Peters saw both
objects on two different nights (27 and 28 March 1880), I've taken the stars
nearer his position as the most likely object. Spitaler's is also possible,
but that would demand an error in Peters's relative positions, possible on one
night, but unlikely on two.
Dreyer also credits N3328 to Tempel, but Tempel gives no position in his fifth
paper, so it is not now possible to tell exactly what he was looking at. He
records two observations, however, so -- like Peters -- the objects must have
appeared nebulous under even pretty good conditions.
=====
NGC 3329 = NGC 3397. NGC 3329 was found by JH; his position is only an arcmin
off the galaxy. NGC 3397, on the other hand, was found by his father in sweep
1096 on 2 April 1801 -- all fifteen of the galaxies that WH found in that
sweep have very large, systematic errors in their positions. See NGC 3752 for
more of the story, as well as h 917 in the "notngc" files.
=====
NGC 3332 = NGC 3342 (which see) is probably the galaxy measured by Schoenfeld
and Vogel, and mentioned in the notes to the GC Supplement by Dreyer. WH's
first observation for H I 272 was referred to Uranus (his "Georgian Planet")
and reduces to a place several arcmin away from the galaxy. But it is the
only one in the area bright enough that he could have seen it, and the
description fits as well.
The galaxy is also number (24) in David Todd's list published as part of his
search for "the trans-Neptunian" planet (see NGC 3604 for more on this). His
sketch matches the sky very well, but his position, like WH's, is not very
good. This must be one of the Todd objects for which Dreyer suspected an
identity with a known nebula, as he does not mention Todd's observation of
this object.
=====
NGC 3333. Lewis Swift picked this up on 30 December 1897, more than 60 years
after John Herschel discovered it on 2 February 1835 at the Cape of Good Hope.
Herschel described it as "eF, vS, mE; appended like a tail to a * 15m." Swift
was also taken with the star (see that story under NGC 3260).
In spite of an entry in Swift's combined 11th list in AN 3517, this nebula
does not appear in the second IC. Herbert Howe writes in his big MNRAS (61,
29, 1900) paper that "Swift says in a letter that these [numbers 115 and 116
of the 11th list] are to be dropped. The former is evidently identical with
the h nebula 3333. The '* 15 att' is of mag. 13, and directly south of the
nebula." Dreyer fortunately saw this note and took Howe at his word, so
omitted Swift's object from the IC.
Dreyer also omitted the second object, list 11 number 116. This appears in
three other of Swift's papers as number 25 of his 6th list of nebulae found at
the Lowe Observatory. The information is the same in all four papers:
1897 Dec. 29 10 36 00 -35 05.4 eeeF, eS, R; eeF D* nr s.
There is nothing in this position, and as Howe apparently had no other details
on why Swift deleted the object, we can only suppose that he (Swift) searched
for it on at least one additional night and did not recover it.
=====
NGC 3335. See IC 625.
=====
NGC 3339 is a faint star preceding NGC 3340. Marth's positions for both
objects (found the same night) are good, and his descriptions apt.
=====
NGC 3340. See NGC 3339.
=====
NGC 3342 = NGC 3332 (which see). WH did not do well with his positions for
this galaxy. His first observation of it (on 18 Jan 1784 as III 5), fully
related by Dreyer in the 1912 Papers, reads "The faintest and smallest nebula
imaginable. I viewed it a long while and with a higher power than the
sweeper. Having no person at the clock, I went in to write down the time and
found it impossible to recover the nebula. It appeared like a vS nebulous
star, and is probably of the cometic sort; there was another vS star south-
following (I think, or rather, am pretty sure), and it preceded a pB * [the
nebula is south-preceding of a star by a diagram, about 6 arcmin][JLED]. It
should have been secured before I went into the light. Its place must be
about 2 1/2 deg following rho Leonis and about 10 arcmin more north than that
star."
WH's vivid description of the field is clear enough to unmistakeably identify
N3342 with N3332, even though his position is over 2 minutes of time, and 15
arcmin off. Dreyer notes that neither Spitaler nor Bigourdan could find the
object -- understandably, given the data they had.
He has two other observations, somewhat better, of it as H I 272 (= N3332),
but even those led to questions about its position.
=====
NGC 3345 is a conflation of a double star found by JH and NGC 3351 = M 95. JH
was looking for his father's H I 26, but did not find it at the recorded
position. That position turns out to be just one minute of time preceding,
and 20 arcmin north of M 95, the description fits the bright galaxy, and WH
did not mention M 95 in the sweep; so -- as Dreyer suggested in the NGC Notes
and in his 1912 "Corrections to the NGC ..." MN paper -- H I 26 is probably an
observation of Messier's object. Wolfgang, going through WH's observations in
considerable detail, agrees and emphasizes the identity with M 95. I don't
believe that we should totally ignore JH's observation, however, so have
listed it under the NGC number 3345.
JH's position for the double is good, though he seems to have doubted his
observation, calling the object "eF, hardly visible." Though Dreyer adopted
JH's description as well as position for the NGC, he noted the identity with
H I 26 as very questionable, and also noted that neither he nor d'A could find
anything at JH's place.
The GC entry is an amalgam of WH's description ("cB, pL, E, mbM") and JH's
position. Dreyer recognized the discrepancy between the descriptions, so
cleaned up the entry for the NGC.
=====
NGC 3351 = M 95 = H I 26. See NGC 3345.
=====
NGC 3355 could be any of a number of galaxies scattered over a 3x3 degree area
near the nominal position. Found by S. P. Langley with Harvard's 15-inch
refractor in April of 1866, he noted the position as "approximate." He was
looking for Biela's comet at the time, so apparently recorded only a crude
position for his nebula.
ESO and SGC took the large late-type galaxy ESO 501-G079 as the most likely
candidate, but this has a very low surface brightness and would be difficult
to see in a long-focus telescope. A more likely candidate is ESO 501-G080, a
"normal" early-type object with a surface brightness two magnitudes brighter
than G079. Langley's position, however, does not fall very close to either
object, so without further information from the historical record, these
identifications can be no more than suggestions.
=====
NGC 3366 = IC 2592. JH has a note: "The minute of RA is doubtful. The
written record makes it 47; but as this is impossible from the context, 37 is
assumed." Dreyer only noted in NGC that the RA was "very doubtful" and that
the bright star that JH saw nearby was not in two catalogues.
The actual RA is 27 (B1830); that is allowed in the context of the sweep. The
next non-stellar object in the sweep is NGC 3446 at RA 10 44 44.6 (B1830), and
the preceding object is NGC 3261 at 10 21 46.6 (again B1830). JH assumed a 10
minute error, but the actual 20 minute error still fits into the sweep.
The galaxy was rediscovered by Delisle Stewart on an Arequipa plate taken
about 70 years after JH's sweep. Stewart made no errors in this entry, but he
also did not note that NGC 3366 was missing. Perhaps the nominal position is
off the edge of his plate. Since he used a one-hour plate (number 3636), he
did not give the central position of the plate, but simply included the plate
number in a long paragraph of one-hour plates that he searched.
=====
NGC 3371 is probably NGC 3384, and NGC 3373 is probably NGC 3389. JH's
descriptions are appropriate for the galaxies, and his measured position
angles -- 68.4 deg between his first and second objects, and 156.8 deg between
his second and third -- are a close match for those between N3379 and N3384
(66.5 deg), and N3384 and N3389 (154.7 deg), especially when precession is
taken into account.
However, JH has left us positions that suggest that these are companions of
NGC 3367, not NGC 3379. His position for N3367, the nominal first of the
three, exactly matches the position for that object measured on another night
when the additional two objects were not seen. Added to this is his
observation of N3389 on the same night the two questionable objects were seen.
Even so, my feeling is that he has somehow confused his observations of N3367
and N3379 on the night when he also measured the two companions.
Adding more mystery to the case is Peters's comment: "[N3371] was distinctly
seen by me 1880, Mar. 2; but [GC]2198, the third of the 'triple nebula,' could
not be found." (Peters's position is within 10 arcseconds of JH's.) There
are two faint stars within two arcmin of the nominal position for N3371;
perhaps Peters saw one of these. Dreyer notes in the GC Supplement that no
other observer had seen either N3371 or N3373 at JH's positions.
-----
Checking the sweep, I find that JH did not measure the positions for NGC 3371
and NGC 3373. Instead, he has offsets -- the position angles that he
published and [delta] RAs ("53" between his first and second objects and "24"
between his second and third. I assume these are seconds of time; he has no
units shown). I don't see [delta] NPDs, but it seems obvious that JH must
have made a mistake in his calculation of the positions from the offsets.
This leaves only Peters's observation to explain. Did he perhaps adopt JH's
position more or less blindly? I would be surprised if he did, so his
observation is still a mystery.
=====
NGC 3372 is the nebula surrounding eta Carinae, or as JH knew it, "eta Argus".
I've taken the position to be in the "keyhole", while JH chose the star itself
to represent the complex nebulosity; I've given the star separately.
Note that the ESO position is nearly twelve arcminutes south at the
intersection of the three great wedges of nebulosity that we see on wide field
images today ("Pearls of the Southern Sky" by Dieter Willasch and Auke
Slotegraaf has just such an image). But this spectacular degrees-wide field
of nebulosity is not JH's object; he described, sketched, and catalogued only
the brightest, central region.
=====
NGC 3373 is probably identical with NGC 3389. See NGC 3371.
=====
NGC 3382 is probably just two stars, if it is indeed anything on the sky. It
was found by Ralph Copeland (or perhaps the fourth Earl of Rosse) on 5 April
1874, who provided this description: "About 4 min p [NGC 3432]. pF, cL, R, bM,
*14 mag in centre. *9 Pos 238.0, Dist 173.7." There is no nebula within a
reasonably large field around the nominal position that matches that
description.
On 24 March 1878, Dreyer himself (or perhaps LdR) noted "4.0 min p and 6
arcmin +- n of [N3432]. vF, S, irr R, only a S group of sts. *9 Pos 192.0
deg, Dist 162.9 arcsec." This position is about an arcmin east-northeast of
two faint stars where there is nothing else to be seen. There is a 10th mag
star south-southwest of the widely-separated pair, but neither its distance
(about 166 arcsec) nor position angle (about 192 deg) from the pair closely
match Copeland's measurements. The agreement with Dreyer's lends some
credence to the identification with the two stars, so I am fairly comfortable
with them as Dreyer's object.
I've entered the mean position of the two stars in the main table, but it
seems more likely to me that Copeland misidentified his reference galaxy:
rather than being N3432, it is perhaps some other object.
There is a clue in the printed observation dates. There is no observation
recorded from Birr of NGC 3432 on 5 April 1874 (there is one, however, on 24
March 1878, apparently by Dreyer): How is it that Copeland refered his
observation of NGC 3382 to it if he did not observe it on the same date?
(Probably pretty easy to do; we should see if the original log books still
exist at Birr.) Other objects observed on 5 April 1874 include NGC 3182, NGC
3188, and Copeland's Septet (NGC 3745 et al.; see the story under NGC 3743).
However, none of these have galaxies -- or even stars -- at the offsets noted
by Copeland for N3382.
Let's look instead at the date on which NGC 3432 was first observed, 18 March
1876. Other objects from that night that might be the reference object for
N3382 are NGC 2718, NGC 2974, and NGC 4152.
Only NGC 2974 has a galaxy near the offset: CGCG 007-015 at 09 38 29.86,
-03 34 49.9 (J2000; 2MSP). The star, at 09 38 17.29 -03 35 48.6 (J2000, Ty2)
is at bit further than claimed -- 197 arcsec rather than 174 arcsec -- and at
a different PA -- 252 deg rather than 238 deg. Finally, there are two other
stars, nearly as bright as the one Copeland measured, and at about the same
distance from the galaxy, south-southeast and east-northeast. But the general
configuration is approximately what Copeland has recorded, so I've included
the galaxy as a distant possibility.
=====
NGC 3384 is probably also NGC 3371, which see.
=====
NGC 3385. See NGC 3386.
=====
NGC 3386 and NGC 3387. John Herschel found these two and NGC 3385 (which is 4
arcmin south of N3386). They were reobserved by d'Arrest whose positions for
N3385 and N3386 match Herschel's. However, d'Arrest placed N3387 very close
following N3386. The Sky Survey shows nothing near d'Arrest's place except a
very faint star that Herschel did not mention. The NGC adopted d'Arrest's
position for NGC 3387.
This turned out to be a mistake because very close to Herschel's position is a
triple star. Brian Skiff has found that the two southern stars share a common
proper motion, while the northern is apparently only an optical companion.
There is a star east-northeast the triple that is probably Herschel's "B *
near."
Additional notes: CGCG calls the northern object "N3386/87" and notes it as a
"double nebula." The MCG also calls it "N3386-7," but assigns the companion a
magnitude of 19 and places it 0.3' northwest -- which describes its position
and appearance exactly, and which makes it far too faint and in the wrong
position relative to N3386 to have been seen by Herschel or d'Arrest.
=====
NGC 3387 is a triple star. See NGC 3386 for the story.
=====
NGC 3388, found by Ainslie Common with his 36-inch reflector, is probably
NGC 3425. The declination is about right; and though Common's RA is 3 min too
small, he marked it "+-" and his brief description ("F, R") is appropriate.
=====
NGC 3389 is probably also NGC 3373. See NGC 3371 for the story.
=====
NGC 3392. See NGC 3394 and NGC 4512.
=====
NGC 3394. JH's RA -- adopted in the GC and NGC -- is 45 seconds too large.
WH's RA is much closer to the truth, though we can't blame JH for preferring
his position to his father's. Dreyer noticed the difference but, lacking any
other observations, could do no more than comment on it.
The only confusion that this causes is with NGC 3392 which is about 4 arcmin
northeast, not northwest as implied by JH's observations. Though WH's
positions are 2-3 arcmin northwest of the objects, his relative position is
good, as are his (and JH's) descriptions. Most modern catalogues seem to have
got the identities straight.
Also see NGC 4512 for more on the sweep in which JH found this object.
=====
NGC 3395 = IC 2613, which see.
=====
NGC 3396. See IC 2613.
=====
NGC 3397 = NGC 3329, which see.
=====
NGC 3398 = IC 644. Considerable confusion has surrounded the identification
of this object and its neighboring galaxies. The original observation is due
to William Herschel, who found a "vF, S, E 20deg sp nf, er" nebulae on 17
April 1789 2m 11s preceding, 0d 50' north of 44 UMa. Reducing these offsets,
taking the proper motion of 44 UMa into account, gives the position (for 1950)
10 48 24, +55 41.1.
There are four galaxies in the area that might be the one that Herschel saw.
Here are data for them:
RA (1950.0) Dec B_t PA Type MCG CGCG UGC IC
Notes
10 48 28.4 +55 39 23 14.55 73 SA:(rs:)ab? +09-18-038 267-18 5954 0644
* superposed 0.55 sp
10 48 32.1 +55 43 53 15.6 130 SA:(rs?)0^+ +09-18-039 267-19 -- 0646
10 48 44.8 +55 39 04 -- 55: E2/S0^-: +09-18-041 -- -- --
10 48 59.9 +55 51 56 14.82 20 SAB(s)cd III +09-18-043 267-22 5976 --
Sev F sts, knots, comps near
On the face of it, UGC 5976 is the most likely candidate: it is second
brightest, the position angle is correct, it is knotty, and it is the largest
of the galaxies in the area. However, its position is well off of Herschel's,
and it has the lowest surface brightness of any of the galaxies here. I think
it is doubtful that Herschel would have picked it up while sweeping.
Instead, Herschel's position falls near UGC 5954, the brightest galaxy of the
four, and also the one with the highest surface brightness. This means that
it is the one that Herschel would be most likely to see. The position angle
is at least in the correct quadrant, and Herschel's note "extremely mottled"
could well be due the presence of the star near south-preceding combined with
the galaxy's bright nucleus and pseudo-ring of uneven brightness.
Still, visual verification of this theory would be nice to have.
Finally, the identity of the two IC objects in the area -- I644 and I646 --
is unambiguous. While Swift's positions are often none too good, they are
at least adequate in this case. The offset in RA is about 12 time-seconds
for both, while the declinations are within a minute of arc. I644 turns out
to be identical to NGC 3398, while I646 is MCG +09-18-039.
=====
NGC 3401 may be a triple star. WH was the only one to observe it, his
observation was apparently rushed (his description reads only, "eF, no time to
verify"), and his data are not internally consistent. His table places it 5
min 42 sec preceding and 23 arcmin south of 56 Leonis. However, in his note
in the 1912 Scientific Papers, Dreyer says, "In the sweep, it is 1.9 min p, 3
arcmin n of II 131 [N3423]." Reducing these two offsets leads to positions
separated by 1 min and 5 arcmin. There is nothing at either position.
Between five to ten arcmin southeast of the position reduced from the N3423
offset (10 46 45, +06 09.5; B1950.0), there are one or two asterisms of stars
that WH might have picked up. The positions are far enough off, however, that
I doubt these stars are WH's object.
However, Jeffrey Corder has suggested that the triple star listed in the
position table may be object that WH stumbled over. It has about the right
total magnitude, and Jeff describes it as "... fuzzy-looking and hard to
resolve." It is also reasonably close to WH's position, so could well be his
object.
=====
NGC 3402 is most likely a reobservation of NGC 3411. Common admits that his
positions are approximate, and his sparce description "F, R" is appropriate
for the galaxy.
LEDA has chosen a much fainter galaxy close to the NGC position. I doubt,
however, that even a observer of Common's experience using his 36-inch
reflector would be able to dig this out.
=====
NGC 3403. See NGC 3752.
=====
NGC 3404 = IC 2609. Common's declination for N3404 is about 14 arcmin off,
though his RA is close. Even though Dreyer has the corrected NPD in the
IC2 Notes (from Herbert Howe), he did not make the connection with IC 2609.
Nor did Bigourdan, who redisovered the galaxy and made it a "nova". He
searched twice for N3404 at its nominal position, but only saw some faint
stars in the area. His observations of the galaxy are good, though; reduced
with respect to a modern position for his comparison star, they fall within a
few arcsec of the nucleus.
Knox Shaw, in Helwan Observatory Bulletin No. 15, also made the correction to
the Dec of the NGC object. He was also the first to suggest the identity,
repeating the position of N3404 for I2609, but putting a question mark on the
note: "? = NGC 3404. There is, however, a vF, vS neb. susp. 1.2 arcmin n and
0.4 arcmin f 3404." This, of course, is not IC 2609.
=====
NGC 3405. Though Marth says "close to a small star", the second object is
really another galaxy. Marth presumeably saw the brighter, larger galaxy on
the southwest as nebulous, so this is the object that bears the NGC number.
=====
NGC 3411 = NGC 3402, which see.
=====
NGC 3414. A faint companion -- which we now call 2MASX J10511304+2800221 --
was picked up by Bindon Stoney and R.J. Mitchell with LdR's 72-inch reflector.
See the "notngc" files under "NGC 3414 companion" for the story.
=====
NGC 3421 = IC 652 and NGC 3422. Among the nebulae found in 1880 by A. A.
Common are two that received these NGC numbers. Common gave them a single
rough position -- there are only faint stars near it. However, ten arcmin
south is a pair that he could have easily seen in his 36-inch reflector.
One of these was later picked up by Javelle, but because the position is so
different -- and because Javelle misidentified his comparison star, driving
his position even further south -- it was not recognized as one of Common's
nebulae until I stumbled across it during work on SEGC. Javelle's object is
in IC1 under the number IC 652, which see.
Herbert Howe measured one of the galaxies, N3421, on two nights, but missed
the other, probably because there is a much brighter star less than an
arcminute to the south. Howe also commented about the possibility of two
other nebulae in the field, but there is nothing at his approximate places
(1.5 arcmin north, and 12 seconds preceding and 2 arcmin south) but faint
stars.
=====
NGC 3422. See NGC 3421.
=====
NGC 3423. See NGC 3401.
=====
NGC 3425 is probably also NGC 3388, which see.
=====
NGC 3427, creditted in the NGC to Tempel, was also seen by David Todd during
his search for "the trans-Neptunian planet". It is Todd's number (4). See
NGC 3604 for more.
=====
NGC 3428 = NGC 3429. Both positions -- from Marth in 1865, and Common in 1880
-- are pretty good. I'm surprised that Dreyer did not catch the identity.
Perhaps if one of the observations had been by one of the Herschels he might
have.
In any event, the identity is secure.
=====
NGC 3429 = NGC 3428, which see.
=====
NGC 3430 is not IC 2613, which see, in spite of being noted identically equal
to the IC number in CGCG. The IC number applies to NGC 3395 instead.
=====
NGC 3432. The nucleus of this edgewise, late-type spiral is hidden behind the
arms and dust of the near side of the galaxy. So, the position is not well-
determined. Most of the positions in the table probably apply to various
knots along the spine of the galaxy. I'm inclined to give high weight to the
infrared positions, so have chosen to take the mean of two 2MASS PSC values as
the preferred position. This is obviously still uncertain.
Also see NGC 3382.
=====
NGC 3436. This is Todd's 6th nebulous object found during his search for
"the trans-Neptunian planet" with the USNO 26-inch refractor (see NGC 3604 for
more about Todd's list). As usual, he gives sketches of the field done
through both the large refractor and its 5-inch finder. These clearly
identify N3436 as CGCG 038-039. Also as usual, Todd's nominal position is
well off. I hope he would have done better had he found his planet ...
=====
NGC 3443. Swift's declination is 8.3 arcmin too small, but the identity is
still clear. See IC 884 for more.
Even though the identity is clear, the nucleus is not. Though the galaxy is
inclined by only 60 degrees to the line of sight, and the central region is
pretty clearly seen, there is no obvious nucleus. The SDSS image shows a
very short, very faint bar with arms springing off its ends (the structure is
the same as the LMC), but bar is nearly uniformly bright. The SDSS has four
different positions listed for "objects" near the center of the galaxy, but
just looking at the image, it's not obvious which one to take as representing
the galaxy. So, I've simply taken the unweighted mean. This agrees pretty
well with the position that I estimate on the DSS2R image, and with the GSC3
position as well, so I've taken the mean as being the "best" position for the
object.
=====
NGC 3445 has an interacting companion. It was actually seen by R.J. Mitchell
with LdR's Birr Castle "Leviathan". See the "notngc" files under "NGC 3445
companion for more."
=====
NGC 3446. JH has two positions for this: one for the brightest star (perhaps
foreground?) CoD -44 6866, the second for the cluster itself. He made the
cluster only 7 arcmin across, so Brian's inclusion of the sparcer group
northwest of the bright star might make astrophysical sense (if the group in
fact is part of the cluster), but it is not JH's object. So, the position
I've taken (from ESO-B) is close to JH's own second position.
ESO 264-G027, a background galaxy, shines through the eastern side of NGC
3446. The two objects make a nice sight on the Sky Survey images. The total
V magnitude of the galaxy, though, is about 13.7 (from B_T and R_T in ESO-LV),
so it would probably not be that striking a sight at the eyepiece.
Also see NGC 3366 where the cluster figures in the identification of N3366.
=====
NGC 3448 is one of the "classic" I0 galaxies. Its nucleus is hidden behind
an array of dust and knots with a short dust lane almost directly across the
center of the galaxy. Looking at the wonderful SDSS image, it's easy to see
where the nucleus should be. Indeed, there is a 2MASS PSC source very close
to that location, so that is the position I've chosen for the galaxy.
=====
NGC 3457 is a bit of a puzzle. It was catalogued by JH who describes it as
"Stellar. 2 or 3 stars with a nebulous blur observed by Mr. Bailey." (Is
Mr. Bailey perhaps an observing assistant?) This is an excellent descripiton
of IC 656 (a triple star, which see), but JH's position is very close to NGC
3460 (also which see). The description is persuasive, but JH usually does
better with his positions: his declination is appropriate for either object,
but his RA is 18 seconds off the triple star. Since it is only 1.5 seconds
off the galaxy, that argues almost as persuasively for the identity with NGC
3460.
Frankly, I'm undecided on this one, so have left the number ambiguous in the
main table.
=====
NGC 3460 and N3461 were first seen as a pair by LdR in 1854, then again in
April of 1878. In March of that year, he says "Setting for this, I found an
eS Cl with a * 12m in Pos 175.1 deg, Dist 305.0 arcsec." There is nothing in
the area which matches this description as the star south-southeast of the
galaxy is only 4 arcmin away, while that south-southeast of IC 656 (a triple
star, which see) is over 6 arcmin distant.
In LdR's 1880 monograph, Dreyer lists all the observations under the GC number
for NGC 3457 (GC 2256 = h 793; which see), but as I note there, it's not clear
that NGC 3460 was the object JH and his Mr. Bailey saw. Swift picked up the
galaxy in 1885; it is the 9th nebula of more than a thousand which he
catalogued as "novae." Given the difference in his RA and JH's (23 seconds),
both he and Dreyer can be forgiven for thinking he had found a new nebula.
Since there is no question about the identity of NGC 3461 -- it is the faint
galaxy about 5.5 arcmin north-northeast of the brighter galaxy -- and since
LdR saw the two as a pair twice, it makes sense to retain the number NGC 3460
for the bright object. I'm not so sure what to do about the number NGC 3457
(which see for more) -- it could belong to the brighter galaxy, or it could be
for the triple star along with IC 656.
=====
NGC 3461. See NGC 3460.
=====
NGC 3462, discovered by WH, was also seen by David Todd during his search for
"the trans-Neptunian planet". It is Todd's number (5). See NGC 3604 for
more.
=====
NGC 3465. Though credited only to JH in the NGC, this is probably also
H III 967 (see NGC 3500 for more on this). WH found the galaxy on 2 April
1802, but it -- and the other fourteen in sweep 1096 -- has a large,
systematic error in its position. Dreyer attempted to sort out the problem in
his notes to his 1912 edition of WH's Scientific Papers; most of his
conclusions are correct. See NGC 3752 for more, and for the correct solution
which Wolfgang Steinicke finally worked out. Also see NGC 3484 for an
unsolved mystery possibly related to NGC 3465 -- but probably not. Finally,
this plays a peripheral role in the identification of h 917, which see in the
"notngc" files.
=====
NGC 3472 may be ESO 572-G025, just an hour off of Stone's position -- but I
don't think so. There is a bright double star, with a fainter star closer to
the galaxy, just two arcmin to the southwest of the galaxy. Given his many
other notes of bright stars near his nebulae, Stone would almost certainly
have mentioned this in his description, and he does not. The entirety of his
description is "Mag = 15.5, Dia = 0.4, R, gbM." He has left no sketch for us,
either.
So the ESO galaxy is a possibility, but no more.
=====
NGC 3473. While looking for this galaxy with the Parsonstown "Leviathan",
Dreyer stumbled across CGCG 095-086. See its entry in the "notngc" files for
more on this mistaken identity.
=====
NGC 3474. See IC 884.
=====
NGC 3476 is probably also NGC 3480 (which see), and NGC 3477. The two smaller
numbers apply to nebulae found by Marth. His relative positions are good, but
are offset from the true positions by 3 arcmin in declination. His
descriptions are apt, so there is little doubt about the identifications of
his two objects.
=====
NGC 3477. See NGC 3476.
=====
NGC 3478. Just as Dreyer misidentified NGC 3473, so did Copeland misidentify
this galaxy -- the big reflector at Birr Castle was not very good at absolute
positions or pointing. See UGC 6076 in the "notngc" files for more on this
particular case.
=====
NGC 3479 = NGC 3502, which see.
=====
NGC 3480 is probably NGC 3476. It is the 11th in Ainslie Common's list of
nebulae found by him with his 36-inch reflector in 1880. None of his
positions are very good, and this one seems to be worse than most -- there are
no galaxies within 10 arcmin of his place.
However, NGC 3476, the largest and brightest of a group, is about 12 arcmin
southwest. It would probably match Common's scanty description ("Small,
stellar"), even as seen in a fairly large telescope.
It is possible that NGC 3480 is the same galaxy as NGC 3490. But that is also
one of Common's discoveries (on the same night? he does not give us dates of
observation), and is a fainter object as well. So, I think it a somewhat less
likely candidate -- but other observers have rediscovered the same object,
even on the same night (see e.g. NGC 1269 = NGC 1291).
=====
NGC 3481 looks like one of the rare "ring" galaxies with a "nucleus" on the
ring itself, and a hole in the galaxy where the nucleus normally would be.
In this case, however, the nucleus appears to be elongated into a bar, and the
remainder of the ring could be interpreted as distorted spiral arms springing
from the ends of the bar.
I give positions for both the "nucleus" as well as for the entire galaxy.
=====
NGC 3484 = h 802 is lost. JH gives a position, suggests that it might be
H III 967 (but that is NGC 3465), and says, "A very doubtful object." That's
it.
Dreyer searched for this on the Greenwich plates that he asked to have taken
of the area covered by one of WH's very strange sweeps (see NGC 2938, NGC
3752, as well as h 653 and h 917 -- both in the "notngc" files -- for more).
I've searched for it on the POSS1 prints. There are no candidate galaxies
within 30-40 arcmin of JH's position. So, we just have to take JH's word for
it -- "A very doubtful object," indeed!
=====
NGC 3487. Swift's RA is about 35 seconds of time too small, but his Dec is
good, and his description appropriate, for UGC 6092.
=====
NGC 3489. See NGC 3498.
=====
NGC 3490. Common's RA is marked "+-", but it is close enough to CGCG 066-080
(and the Dec is within an arcmin), to make the identification pretty certain.
There are other equally bright galaxies around (including NGC 3480, which
see), but none at the right declination.
=====
NGC 3494 is may be the double star 8-9 arcmin north of NGC 3495. Tempel says
only (in a very crude translation by yrs trly), "Six arcminutes north of the
middle knot [of three in N3495], I repeatedly saw a very small nebula, which
at first sight I took to be [part of] N3495." There is nothing in the
implied position (calculated by Dreyer from N3495's position), but the double
is only 3 arcmin further north, and is of similar brightness to other stars
that Tempel mistook for nebulae.
Jeffrey Corder wrote in January 2009, however, suggesting that one of the
knots in NGC 3495 itself may be NGC 3494. I've looked at the field using the
DSS and am skeptical. Aside from its nucleus, the brightest knots in N3495
are to the south, and only an arcminute away from the nucleus. Jeff, of
course, has the advantage of having actually seen the galaxy and its field.
But Tempel was an experienced observer, too. I can accept easily that he
might have made one mistake in his description, but two begins to stretch
credibility.
However, I've marked the double star with a colon. I'm clearly not sure about
the identification, but don't see a better alternative closer to the galaxy,
either. So, maybe ...
=====
NGC 3495. See NGC 3494.
=====
NGC 3497 = NGC 3525 = NGC 3528 = IC 2624. This object may hold the record as
the one with the most NGC and IC numbers. It was independently discovered
four different times, first by WH. As Dreyer noted in 1912 (MN and Scientific
Papers), there is a 6 minute error in the GC/NGC RA. Re-reducing WH's data
in the Scientific Papers leads to the correct position.
JH found it next during his stay at the Cape of Good Hope. He was also the
first to see NGC 3528's brightest companion (N3529 = I2625). He got the
identity with H III 824 correct in his Cape Observations, but separated his
father's nebula from his brighter one for the GC. This suggests that the
six-minute error is JH's rather than CH's. Dreyer copied the GC position into
NGC, so it was not until his work on WH's papers that he noticed the
discrepancy.
Ormond Stone was the next in line -- his position is unusually good: only a
minute of time off (his entry is NGC 3525). The identity is nevertheless
pretty sure as there are no other nebulae in the area that he would have
called magnitude 12.0.
Finally, Lewis Swift picked up the pair in 1898. His RA is nearly correct,
but his declination for N3528 = I2624 is about 5 arcmin too far south, nearly
equal with that for N3529 = I2625. Again, there can be little doubt about the
identity as Swift describes the brighter of the pair as "considerably bright;"
there are no other galaxies near that are bright enough for that description.
It was his observation that gave the pair their IC numbers.
=====
NGC 3498 is probably the triple star three arcmin west-northwest of WH's
position. Dreyer reprints WH's full note in which he says, "eF, not S. I had
some doubt and put on 240, but there being no stars very near it, I could not
adjust the focus, and therefore could not verify it." Dreyer also notes that
d'A could not find the nebula during repeated attempts when N3489 was seen
easily.
=====
NGC 3500 is given as a double nebula with one number in the NGC, while JH in
GC assigns two numbers with a single position. In each catalogue, the
position comes from WH's observations on the night of 2 April 1801 which
suffer from large, systematic position errors (see NGC 3752 for more). Dreyer
more or less sorted out the problems for his edition of WH's Scientific
Papers, based on accurate positions measured on 30-inch reflector plates taken
at Greenwich in 1910 or 1911 (see MNRAS 71, 509, 1911).
Unfortunately, neither Dreyer nor the Greenwich observer(s) assign NGC numbers
to all of the galaxies in that list (I have those listed in my note to NGC
3752). I've taken a bit of a liberty here, and have split out WH's two
numbers, III 967 and III 968, giving the first to NGC 3465 (which see), and
the second to NGC 3500 (this may not be correct; see the next paragraph). I
follow Dreyer's lead on the first, but use NGC 3500 for the second where he
does not.
Looking at WH's original sweep 1096, I'm not totally convinced that this is
the correct solution. In CH's fair copy of the sweep (in the Herschel
Archive), we read for the observation
Two, the 1st vF, vS. The 2nd eF and smaller than the first. It is a little
more north and following, but very near to it.
The phrase "but very near to it" has caught my attention. Given that the
galaxies are nine arcminutes apart -- and NGC 3523 is actually closer (seven
arcminutes) to NGC 3500 than is NGC 3465 -- I wonder if one of the asterisms
in the area might not be a better candidate for one of WH's objects. I have
my eye in particular on the double star at 11 01 24.0, +75 11 34 (J2000) --
but is this brighter than the galaxy as WH suggests? For now, I will just
leave this as a possibility in a sweep with known problems.
=====
NGC 3502 = NGC 3479. The descriptions and declinations of the two entries
(Nos. 180 by Leavenworth, and 181 by Stone) in the first Leander McCormick
list are much the same, but the RA of the following nebula is 4 minutes of
time too large. This is in the same sense as many other of the LM nebulae, so
the identity is pretty certain. The suggestion in RNGC that the galaxy 50
arcmin north and a few tenths of a minute preceding Leavenworth's position
strikes me as considerably less likely since RA errors are more common in the
LM lists than Dec errors, though these also occur, of course.
=====
NGC 3505 is perhaps a reobservation of NGC 3508 (which see). Even though JH's
position is over 3/4 deg off in Dec, his description fits very well, including
the "star 14 near." JH found it during his stay at the Cape. The large
position error is bothersome, but there is nothing else within several degrees
that matches the description.
-----
I checked the sweep and found that JH's nebula was directly preceded by the
star HD 95234 (the offsets are 3m 26s in RA and 4arcmin 50arcsec in Dec).
These give a position for the nebula almost exactly that of NGC 3508, so given
the matching description "pF, R, S, glbM, has * 14 v near", the identification
is secure. I have still not yet been able to reproduce JH's reduction, so do
not know the source of his error. Nevertheless, I'm confident that N3505 is
indeed identical to N3508, so have removed the colons in the position table.
Note, too, that the galaxy is also IC 2622 (which see) found by Lewis Swift.
=====
NGC 3508 = IC 2622 (which see) and is probably also = NGC 3505 (also which
see). WH called this "small" while his son saw it as "vL" -- WH is closer
to the truth. Both positions are good, so there is no doubt that both men
were looking at the same object.
Similarly, Swift's note "... looks like a D *" in his description makes it
clear that he, too, was looking at the same galaxy. In his case, however, the
position is off by a few arcminutes to the northeast.
-----
As noted above, re-reducing JH's observation of NGC 3505 (which see)
definitively shows that it is identical to NGC 3508. His description of the
galaxy in that observation also removes the size discrepancy.
=====
NGC 3514. See NGC 3520.
=====
NGC 3518 = NGC 3122 = NGC 3110. In the original AJ paper, Stone notes, "In
same field with nebula discovered by Stephan." This is a bit puzzling as
none of Stephan's nebulae are within 5 degrees of Stone's nominal position.
Stone has left us a sketch, too, with the same nominal position on the cover
sheet. The sketch shows a nice double nebula with four stars nearby. Again,
there is nothing on the sky within 5 degrees of the nominal position that
matches the sketch.
So, I assumed some sort of error in Stone's position and began looking at
possible digit errors. After ruling out a few, I found NGC 3122 in Stephan's
13th list (it is number 54 there) just an hour of time preceding Stone's
position. Checking his sketch against the PSS, I found that the "double
nebula" is actually the central bulge, and a very bright arm to the
southeast, of a single galaxy. Furthermore, one of the "stars" sketched by
Stone is the nucleus of an interacting companion galaxy, MCG -01-26-013. Were
it not for the sketch, I would assign the NGC number to this companion (though
the position angle is more than 20 degrees off Stone's estimate of 110 deg).
As is, I am tempted to put the number on just the arm -- but that does not
match Stone's description, either. By default, then, N3518 = N3122 = N3110
(which see for another story).
=====
NGC 3520 is another of the Leander McCormick discoveries, this one by
Leavenworth. His nominal position is close to an asterism of 4 or 5 stars
spread over an area of 0.8 by 0.6 arcmin, but his description (m = 15.3, D =
0.4, iR, gpmbM, sev vF sts inv) does not match the appearance of the stars.
In addition, they are too bright, being 13 to 15th magnitude.
A more likely match is to ESO 570- G004, an interacting double system (with
two stars superposed) 1 min 35 sec east and 5 arcmin south of the nominal
position. It matches Leavenworth's description pretty well. The position I
give for the entry includes all four objects.
Other possible matches include the double star at 11 01 55.6, -17 40 23; and
NGC 3514 = ESO 570- G001 at 11 01 32, -18 30.7 (both positions B1950). These
don't match the description as well as the interacting system, however, so I
view them as less likely to be Leavenworth's object.
=====
NGC 3523 is H. II 904 from WH's problematic sweep 1096 of 2 April 1801; all
the positions in that sweep suffer from large, systematic errors. See NGC
3752 for more.
=====
NGC 3525 = NGC 3497 (which see) = NGC 3528 = IC 2624.
=====
NGC 3526 = NGC 3531, which see.
=====
NGC 3528 = NGC 3497 (which see) = NGC 3525 = IC 2624.
=====
NGC 3529 = IC 2625. See NGC 3497.
=====
NGC 3531 = NGC 3526. Holden misidentified the star he noticed 46.5 seconds
preceding the galaxy. When the correct star is used (BD +7 2412, not 2413 as
Holden wrote), his position falls close to that of NGC 3526 = Marth 215. The
descriptions are virtually identical, and Holden notes the star just southwest
of the galaxy.
Spitaler was the first to suggest the identity. He found IC 670 near Holden's
position, but that is fainter and does not agree with either of the earlier
descriptions, so Spitaler -- correctly -- called IC 670 a "nova."
=====
NGC 3533 = "NGC 3557A," which see.
=====
NGC 3537 is an interacting galaxy pair about 15 arcmin north-northwest of
N3541, and may have been found by Ainslie Common on the same night that he
found the latter (though he does not give us the dates of his observations).
His position and description is pretty good, being only about 1.5 arcmin off
in Dec. The NGC position is even better, coming from two micrometric
measurements by Tempel in 1881 and 1882.
Nevertheless, RNGC has misidentified it, giving the number to the galaxy that
is properly called NGC 3541 (which see). Curiously, Vorontsov-Velyaminov
skipped over the object for MCG, though he has included many other even
fainter interacting pairs as well as N3541.
There is a bit of a mystery about Tempel's observations, too. He lists them
as separate entries in his table of new nebulae in his fifth paper with no
indication that they might refer to the same object. However, his positions
-- once precessed to a common equinox -- are within a few arcsec of being
identical. Tempel mentions a "star" on one side of the nebula in his second
observation, but not the first. The nebula is described as fainter the first
night, too, being a (WH) class III nebula rather than class II-III.
On both nights, however, he mentions a faint "star" in the middle of the
nebula. I suspect that both his observations apply to the brighter of the two
galaxies; the "star" on the side of the nebula is almost certainly the
fainter object, seen only on the better night.
=====
NGC 3538 is a double star found by d'A. It is identified in the MNRAS 71,
509, 1911 article which helps sort out one of WH's sweeps suffering from
large, systematic position errors (see NGC 3752 for more).
=====
NGC 3540 = NGC 3548, which see.
=====
NGC 3541. Common's position from his short Copernicus list is very close to
15 arcmin south of MCG -02-29-003, and is within 0.2 min in RA. His
description is appropriate for the galaxy as it would be seen in a 36-inch
telescope, so the position is probably due to his misreading the declination
circle. RNGC has the object as non-existent.
See NGC 3537 for more on this field.
=====
NGC 3542. See NGC 3545.
=====
NGC 3543. There is no identification problem with this edgewise galaxy, but
the exact position is indeterminate: the nucleus is lost behind patchy dust
and emission regions. The position I have finally chosen is from the 2MASS
XSC, close to the unweighted mean of all the values that I list in the table.
=====
NGC 3544 = NGC 3571. NGC 3544 was found 8 Jan 1886 UT by Ormond Stone
with the Leander McCormick 66-cm refractor. The cover sheet on his sketch of
the object (made 13 Jan 1886 UT) bears the note "near but prob. not G.C.
2330," in addition to the usual dates, position, magnification, and his
initials.
The position on the cover sheet is given as "11h 4.0m, -17d 41m." This was
rounded off in RA to "11 4" in AJ 7, 9, 1886 where the discovery was
published. The published paper also notes "G.C. 2330?" and there is no
object at Stone's position. Stone's sketch also shows the elongated galaxy in
the correct position angle. Unfortunately, the nearby field stars are not
shown clearly on the sketch. A few specks on my copy are probably dust on the
photocopier, but more or less correspond to nearby stars which Stone could
have seen with the big refractor.
Finally, the positions in the first two lists of nebulae found at LM are often
1-2 minutes of time west of the true positions. Assuming the identity with
N3571, this is one of those cases.
The NGC position for N3571 comes from William Herschel's single discovery
observation on 8 March 1789, but is good enough to identify the galaxy
unambiguously (the position was later verified by Bigourdan at Paris in 1888
and 1900, Kobold at Strassburg in 1901, Porter at Cincinnati in 1906 and 1908
-- though curiously, first by Leavenworth at Leander McCormick in 1887).
The galaxy is just bright enough for Shapley-Ames, and it has been listed
there and in the susequent literature under N3571 as the NGC position for that
number is more nearly correct than the NGC position for N3544. So, in spite
of Paturel's use of the number N3544 in RC3 (he perhaps followed ESO-B which
has the listing as "N3544=N3571"), we should retain N3571 for consistency.
=====
NGC 3545 is a double interacting galaxy. The components are approximately
equal in brightness as judged in DSS images, so I wondered which one Stephan
saw in March of 1884 when he found the object. Re-reducing his micrometric
position suggests that he measured the western galaxy. While he does not
mention the eastern galaxy explicitly, he does suggest that his object may be
resolvable ("... semble resoluble.")
On the same night, he found NGC 3542; his position for that, measured with
respect to the same comparison star, HD 97287, is within 0.6 second of time
in RA, and half an arcsecond in Dec, of the SDSS position. This suggests that
his measurement of NGC 3545 really does apply to the western galaxy.
=====
NGC 3548 = NGC 3540. Both numbers are from JH, but his position for N3548 is
1 min 9 sec too far east. This probably represents a 1 minute error somewhere
along the line from observation to final position, but without JH's original
papers, finding the error will be difficult. The identity of the two numbers
is assured by JH's notes (for NGC 3540) "... a * 7m p, distance 7 arcmin to 8
arcmin" and (for N3548) "... a * 8m precedes." The star is very close to 8
arcmin preceding, and is about 25 arcsec south.
=====
NGC 3550. I've been curious for some time about this galaxy, called a
"double nebula" in CGCG. The object actually looks triple in the DSS image --
or are those superposed stars? I have wanted to examine it on one of the
digital sky surveys.
Finally, the SDSS has covered the area. While the two objects to the north
are certainly galaxies, the southwestern component is quite stellar. However,
2MASS has three acceptable images in its three bands. It appears that all
three objects are galaxies. This is confirmed by the redshifts given by John
Tonry in AJ 90, 2431, 1985 (cz = 11000 km/s for the faint southwestern galaxy,
10447 km/s for the central galaxy, and 10388 km/s for the northeastern galaxy;
all the redshifts have errors of +- 15 km/s).
I have, by the way, taken the object closest to the middle of the entire
image as NGC 3550. It may be better to take a mean position for the entire
triple object.
Note, too, that both JH and Dreyer have notes discussing possible variability
of the galaxy. As Dreyer concludes in 1912 in his edition of WH's papers, the
only really outstanding brightness estimates suggesting that come from JH
himself: His six observations run from "B" to "eF". All the other visual
observations suggest "vF" or "F". There is no hint in the modern literature
of any of the galaxies being a Seyfert, nor have there been any observations
suggesting the existence of a supernova remnant in NGC 3550. JH probably had
to contend with variable seeing and a speculum mirror of variable condition.
Also see NGC 3552 where this figures in the NGC identification problems in
Abell 1185.
=====
NGC 3551 and NGC 3555 are probably the two brightest galaxies in Abell 1177.
Swift's RA's are just +1 minute of time in error.
RNGC suggests that the brightest galaxy is NGC 3555. This would make N3551
one of the triple system about 2 arcmin southwest. However, these galaxies
are considerably fainter than the second brightest galaxy in the cluster,
which is about 3.5 arcmin to the northeast. There is also a star close to the
middle of the three, and I think that the ensemble would appear as a "small
nebulous cluster."
Swift describes his object as "eeF, vS, R, difficult; south of two." His
second he calls, "vF, R, n of 2." It may seem odd that he would call the
brighter galaxy the fainter, but it has a lower surface brightness, and could
well appear fainter at the eyepiece.
Unfortunately, Swift's relative position between the two galaxies (10 seconds
of time, and 30 seconds of arc) matches neither the RNGC interpretation, nor
my own. So, the positions don't help us much in this case. We need some
visual observations to check Swift's descriptions.
=====
NGC 3552 and NGC 3553. William Herschel found two objects in 1785, and
reobserved them in 1790, providing them with separate positions then. John
Herschel has several sweeps over the area, finding four objects altogether.
D'Arrest observed the same four galaxies, and picked up a fifth about 10
arcmin south. A sixth was found in 1885 by Bigourdan who also provided
accurate positions for the other four (he also has one observation of a
"nova" in the field, but his estimated position points at blank sky; see the
discussion of this under NGC 3561). These six nebulae were included in NGC.
Lord Rosse did not observe (or at least left no record of) any of them. If he
had, there would almost certainly be more than the six objects in NGC that
there are, since these six NGC objects are the brightest in the cluster Abell
1185.
At least two other "historical" observations of Abell 1185 exist. First,
Kobold measured accurate positions in 1902 for five objects here (one, which
he called "Kobold 13," was discovered by him). One of his positions (for
N3552) points at blank sky. Three other of his positions are systematically
off the galaxies by about 20 arcsec. Because of the supposed care with which
Kobold did his work, Hubble (in his PhD thesis, published in 1917) was misled
into questioning his own work in the area where he measured positions and
estimated types for several dozen galaxies. We'll come back to this
particular problem in a bit.
With all these positions and observations, one can be excused for believing
that all is well, and that we know exactly which NGC number applies to which
object. Not true! Only the numbers for three of the six NGC galaxies are
pretty solid (N3550, N3554, and N3558). Questions arise for the other three.
If we restrict ourselves to the early observations, we can be pretty sure
which objects were seen by the Herschels and by d'Arrest -- the brightest five
galaxies. While the positions are not exact, they are good enough to pin down
the correct objects. The problems begin with Bigourdan's observations. While
his positions (reduced using GSC positions for his comparison stars) are
excellent, he assigned the number N3553 to the object which John Herschel and
d'Arrest called N3552. For N3552, he chose a faint galaxy about an arcminute
south-preceding. It has a brighter star superposed -- it is actually this
star which Bigourdan measured; he describes the two objects as a single faint
nebulous spot. Dreyer adopted Bigourdan's position for N3553. It's no
surprise then, that the NGC positions for N3552 and 3553 are very close --
they apply to the same object.
For this catalogue, we've followed historical precedent, and assigned the
number N3552 to the brighter north-following object, leaving the
south-preceding object (the one first seen by Bigourdan) as N3553. This is
counter the prevailing idea that lower NGC numbers are always preceding, but
explicitly acknowledges the actual history of the observations.
Well, I promised a brief discussion of Kobold's and Hubble's data. Kobold's
mistake, not found by Hubble, was a transposition of two numbers in the
declination measurement of his comparison star with respect to an FK1
reference star (the comparison star is actually the same star used by
Bigourdan for most of his measurements). This transposition (instead of -9'
42.5" as used and published by Kobold, read -9' 24.5") resulted in a
systematic error of 18.6" in his declinations of N3550, N3552, N3554, and
K13. Once corrected, the positions of N3550, N3554, and K13 agree very well
with those measured by Bigourdan, by Hubble, and with those in GSC. However,
Kobold's position for N3552 points at blank sky -- there is nothing within 3
arcmin in any direction brighter than the POSS1 plate limit. I suspect that
Kobold's offsets apply to another star/galaxy pair, but I've not been able to
find which objects would fit (I admit to not having looked very hard; perhaps
a reader could unravel the mystery).
In any event, Kobold's systematic error misled Hubble into thinking that his
positions, measured on a plate taken with the 24-inch reflector at Yerkes
Observatory, were somehow incorrect. In the end, however, Hubble printed his
own positions and identifications. His positions are quite good, but his
identifications are wrong for N3552 (he got K13) and N3554 (he got N3552); he
did not identify N3553 at all -- but it is his number 81 in his Table XI.
=====
NGC 3553. See NGC 3552.
=====
NGC 3554. See NGC 3552.
=====
NGC 3555. See NGC 3551.
=====
"NGC 3557A" = NGC 3533. There is no problem with JH's position of NGC 3533,
nor with de Vaucouleurs's for "NGC 3557A" as he called it in his Stromlo
survey of southern Shapley-Ames galaxies. De Vaucouleurs simply missed the
NGC entry for N3533.
=====
NGC 3558. See NGC 3552.
=====
NGC 3559 = NGC 3560, which see.
=====
NGC 3560 = NGC 3559. During his MicroSky work, Glen Deen could not find NGC
3560. There is indeed nothing in its position, copied exactly from the GC by
Dreyer, and before that from JH's 1833 catalogue. Checking that catalogue,
though, I found that JH himself equates his 834th object with his father's III
79. The descriptions are similar, and Sir John himself says, "The PD of the
working list is 6 arcmin out, owing to which I have often before looked for it
in vain." So, he must have had the correct polar distance in front of him
when he wrote this. But his NPD is exactly 50 arcmin out. I suspect that the
1833 NPD suffers from a typographical error: in place of "77 53 50," read
"77 03 50."
D'Arrest also noticed the 6 arcmin problem (he also marks the name III 79 with
a question mark, and does not mention JH's number), and has two observations
of this to Sir John's one. Thus, it is d'Arrest's presumably more accurate
position that Dreyer adopted for NGC 3559.
However, Dreyer had only JH's position for h834 to use. This is exactly 50
arcmin in declination out from d'Arrest's correct position for III 79. Since
Sir John had included h834 in GC as a separate object, Dreyer followed JH's
precedent. So, we are left with two numbers for the same object. Curiously,
though, neither Dreyer nor JH have any note in GC or NGC about the identity,
which JH himself had noted over 30 years earlier.
=====
NGC 3561 is usually taken in modern catalogues as the entire double system Arp
105 = VV 237. However, the brighter (southern) of the two interacting
galaxies is the one seen and measured by the visual observers, and by Hubble
in his 1917 thesis. This is the one that I have labeled N3561 in the main
position table.
There is, however, an intriguing observation of a "nova" by Bigourdan about
15 arcsec north of the northern component of Arp 105. The right ascension
offset estimated by Bigourdan, however, places the nova in a blank sky field
four seconds of time preceding the galaxy. I wonder, though, if Bigourdan in
fact saw the galaxy, but misplaced it because of its faintness. The question
is a bit academic now, since the observation only exists in Bigourdan's list;
he apparently did not publish it in any of his lists of new nebulae, so it did
not receive an NGC or IC number.
See NGC 3552 for more discussion about this field.
=====
NGC 3565 and NGC 3566. These two objects were given the same poor position by
Ormond Stone in the first Leander McCormick list. The identification with the
close pair of galaxies listed in the table was made by noting that many of the
first list nebulae were placed about two minutes of time too far west.
Subtracting two minutes from the RA puts the position very close to the faint
pair.
The identification of this pair as NGC 3565 and 3566 is obviously not very
secure because the discovery position is poor, and there are no sketches of
the objects among Stone's papers.
Another possibility is that N3565 and 3566 are identical to IC 2623 and the
star superposed just south. However, this would require a 4 minute error in
Stone's RA, as well as a 4 minute declination error. While a few of the
Leander McCormick positions are indeed this far off, I think that this
possibility is less likely.
Still -- I've been bothered by the identification of the pair as Stone's
objects because they are so close together, and because the optical and
infrared sky surveys show an apparent nucleus BETWEEN the two components.
This strongly suggests that there is but one peculiar galaxy here. Hence the
question marks. I have to question, too -- if this is indeed Stone's pair --
whether he could see both objects.
=====
NGC 3566. See NGC 3565.
=====
NGC 3567. Though most cataloguers have taken the somewhat brighter
northwestern galaxy as the NGC object, I've listed both objects here given
JH's comments. He has this to say about it on 27 Dec 1827: "eF, R, sbM; with
an appearance of stars." On 19 April 1830, he says, "vF; wind furious;
perhaps only F stars." (WH has only "eF; a little doubtful" on 13 April 1784,
the only night he recorded it.)
Perhaps I wouldn't be as impressed with JH's use of the plural "stars" if he
had only used it once. But with it appearing in both of his observations, it
is too striking to ignore.
=====
NGC 3570 was seen by E. Stephan on 15 March 1877. See UGC 3840 in the
"notngc" files for more.
=====
NGC 3571 = NGC 3544, which see.
=====
NGC 3575 = NGC 3162. D'Arrest's RA is one hour too large. He must have had a
bad night on 21 February 1863 since N2753 and N3760 (both of which see) are
his other two novae from that night. In any event, when the one hour
correction is made, d'A's position falls within one arcmin of NGC 3162, and
his description is perfect for the object, including the 11th mag star 3
arcmin west, and the 16th mag star 1 arcmin southeast (actually superposed on
the southeast arm of the galaxy).
=====
NGC 3576. Even though Lauberts marks the identity as questionable, there is
no doubt that this is the object that JH saw. His figure shows all six of the
bright patches of nebulosity in the area, and matches the appearance of the
sky pretty well. He notes that the position for this object (and a couple of
others) comes from two figures he sketched for the group. This may account
for his RA being a bit off for this southwest patch: it is shown too close to
the rest of the nebulae in his sketch published in CGH.
The other nebulae are NGC 3579, 3581, 3582, 3584, and 3586. JH's positions
and descriptions for them are very good.
=====
NGC 3578. JH found this on 16 Dec 1827 along with at least sixteen of his
father's nebulae. Of these seventeen nebulae, only one other (NGC 2848) has a
position in JH's table marked uncertain. This one, N3578, has the NPD given
only to a full arcmin and is marked with a plus-minus sign. JH's description
is also short and discouraging: "A doubtful object, but probably a nebula."
Nevertheless, there is what I earlier took to be a close double star within
JH's usual statistical error of his position. Looking again at this object on
the several DSS images, and on the 2MASS J-band image, I now (November 2014)
think that it is a single star.
There is another double star seven arcminutes south. Given that my first
choice has turned out to be a simple star, I think that the double is perhaps
more likely a candidate than I had first considered it. But the question
marks are staying on it! It is nevertheless, the sort of double star that JH
mistook for a nebula several other times, so I'm going to at least leave it as
a possibility for NGC 3578.
=====
NGC 3579. See NGC 3576.
=====
NGC 3581. See NGC 3576.
=====
NGC 3580 is probably not IC 675, which see for more.
=====
NGC 3582. See NGC 3576.
=====
NGC 3584. See NGC 3576.
=====
NGC 3586. See NGC 3576.
=====
NGC 3588 is a double galaxy not too far south of delta Leonis. It is bright
enough for the Herschels to have seen, but I suspect that the glare from the
star hid it. That is certainly what happened with the SDSS. While the
galaxies can be seen in the SDSS image, the field is covered with glare and
diffraction spikes.
Swift found the object on 26 April 1883 and described it as "cS, vF; f [delta]
Leonis 4s. Easily overlooked." (He miswrote the difference in RA -- the
galaxy actually precedes the star.) It's likely that he saw only the brighter
southwestern galaxy of the pair, but most catalogues list both under the NGC
number. I've followed along with that, and give a combined position for both
objects.
=====
NGC 3594. The NGC position falls between two galaxies that could be the
object WH saw. The "standard" identification is with UGC 6286, though
another possibility is CGCG 268-006, smaller but brighter than the UGC galaxy.
However, it is considerably further from WH's positions than the UGC galaxy.
Checking WH's sweeps (CH's fair copy in the Herschel Archives) gives another
two positions, one from CH's reduction, the second from an offset from "279
Ursae of Bode's Cat." which turns out to be HD 100615. Both of these
positions (given in the position table), are closer to UGC 6286 than is the
position reduced from WH's 3rd list in his Scientific Papers. This suggests
that the usual identification is correct.
However, I noticed that a few other galaxies that WH found on the same night
also had identification problems (specifically those flagged with Notes by
Dreyer in the 3rd list in the Scientific Papers). Curious about this, I
collected all of WH's observations from the night of 14 April 1789 that he
referred to 64 Ursae Majoris. I've listed them here with WH's positions
reduced from the offsets, given in the 3rd list, to the modern position of the
star (corrected for proper motion). The differences, in the sense "True minus
WH" follow, with a few notes appended. I've ordered them by declination; the
reason for that is obvious, and is discussed below.
NGC H RA (2000) Dec Delta Pos (T - WH) Notes
RA Sec Dec Min
3780 I 227 11 38 51 +56 19.0 +31 -2.8
3804 III 773 11 40 16 +56 14.0 +38 -1.9 = NGC 3794
3898 I 228 11 48 40 +56 05.8 +35 -0.7
3594 III 770 11 15 29 +55 45.3 +43 -3.0
3888 II 785 11 47 00 +55 59.8 +34 -1.8
3850 III 776 11 44 34 +55 53.9 +61 -0.7 WH notes "time inaccurate"
3990 II 791 11 57 08 +55 29.6 +28 -2.1
3998 I 229 11 57 29 +55 28.6 +27 -1.4
3913 II 786 11 50 25 +55 20.7 +14 +0.5
3972 II 789 11 55 22 +55 19.6 +23 -0.4 Obs includes N3977=N3980
3916 II 787 11 50 53 +55 08.7 - 2 -0.1
3921 II 788 11 50 48 +55 05.7 +19 -1.0
3737 III 772 11 35 21 +54 58.2 +15 +1.3
3733 III 771 11 34 47 +54 50.2 +15 +0.8
3738 II 783 11 35 41 +54 32.2 + 8 -0.7
3756 II 784 11 36 38 +54 19.1 +10 -1.4
3656 II 782 11 23 34 +53 49.8 + 5 +0.7
3631 I 226 11 21 11 +53 08.9 - 8 +1.3
3824 III 774 11 43 28 +52 43.9 -43 +2.9
3829 III 775 11 43 47 +52 40.9 -20 +1.8
Mean Delta +16.7 -0.44
Sigma n +- 5.1 +-0.34
Sigma 1 +-22.8 +-1.54
Note that the largest declination and RA offsets occur at the extreme northern
and southern limits of the sweep. While the mean RA difference is west by
16.7 seconds of time (or about 2.4 arcminutes at the mean declination), and
the mean Dec difference is 0.44 arcmin north, the trends in both RA and Dec
with declination are clear. I'm going to suggest that, as on the notorious
night of 2 April 1801 (see NGC 3752 for details), WH was not sweeping along
the meridian, but along a great circle turned at some small angle to the
meridian.
All this suggests that UGC 6286 is indeed WH's galaxy, and is the correct
identification for NGC 3594.
=====
NGC 3596. See NGC 3616.
=====
NGC 3599. See NGC 3632.
=====
NGC 3604 = NGC 3611. WH's RA is one minute too small, but his description is
apt for NGC 3611. Dreyer, without benefit of wide-field plates, comments in
his notes to WH's catalogue, "Should probably be rejected, together with III
88 (sic) and III 598 (NGC 3509), the only other neb this night, as there was
fog `which indeed was so strong as to make everything swim about me.' " NGC
3509 is also a minute of time east of WH's RA, reinforcing Reinmuth's
suggestion of the identity of N3604 with N3611.
I'm not sure, however, which object Dreyer means by "III 88." III 88 is
NGC 3401 (which see), and was found two and a half years earlier than the
other two objects. In WH's catalogues, only NGC 3509 is noted as being found
on the same night (30 Dec 1786) as N3604. Did Dreyer mean to have only III
598 in his comment? Probably so, but we can't be sure without seeing his MS.
Coincidentally, this object is also the first of 36 numbered and lettered
nebulae and stars that David Todd found during his 1877-1878 "Telescopic
search for the trans-Neptunian planet" with the USNO 26-inch refractor. He
has given us a nearly complete transcription of his observing notes in his AN
2698 article; this makes digging out the nebulae, and all the comments about a
single object, rather more difficult than is ideal. Also, Todd's positions
are very crude (apparently read from the refractor's setting circles), though
he has given us sketches of each object's field so that we can still
positively identify all but one of his objects (Dreyer, I'm sure, would have
done this had he had a sky survey at hand). Todd found at least two other
objects which were bright enough that he (correctly) assumed them to be known
nebulae.
Several people, including Wolfgang Steinicke, Steve Gottlieb, Klaus Wenzel
(inspired by one of Wolfgang's articles), Courtney Seligman, and me, have
tackled the list. Here are the identifications of each of his sketched
objects.
Todd's Modern name Type Note
number
(1) NGC 3604 = NGC 3611 Galaxy
(2) GSC 0838-0889 Star
(3) GSC 0848-1219 Star
(4) NGC 3427 Galaxy
(5) NGC 3462 Galaxy
(6) NGC 3436 Galaxy
(7) --- --- See comments below.
(8) IC 669 Galaxy
(9) NGC 3685 Galaxy
(10) NGC 3849 = IC 730 Galaxy
(11) NGC 4075 Galaxy
(12a) NGC 4073 Galaxy
(12d) NGC 4063 Galaxy
(13a) NGC 4045A Galaxy = CGCG 013-045
(13b) NGC 4045 Galaxy
(13e) CGCG 013-049 Galaxy
(14a) NGC 4077 = NGC 4140 Galaxy Same as (16a)
(14b) NGC 4139 = IC 2989 Galaxy Same as (16b)
(15) NGC 4179 Galaxy
(16a) NGC 4077 = NGC 4140 Galaxy Same as (14a)
(16b) NGC 4139 = IC 2989 Galaxy Same as (14b)
(17) NGC 4355 = NGC 4418 Galaxy
(18) NGC 4202 Galaxy
(19) GSC 0836-0339 Star
(20a) UCAC 514-051250 Star
(20b) NGC 3153 Galaxy
(20c) HIP 50085 Star This is not CGCG 064-091.
(21a) NGC 3134 Galaxy
(21b) UCAC 512-048943 Star
(22) IC 591 Galaxy
(23) CGCG 064-093 Galaxy = MCG +02-26-033
(24) NGC 3332 = NGC 3342 Galaxy
(25) CGCG 066-007 Galaxy = UGC 5864
(26) CGCG 065-074 Galaxy = MCG +02-27-033
(27) GSC 0841-1088 Star
(28) CGCG 065-073 Galaxy
(29) NGC 3217 = IC 606 Galaxy
(30) NGC 3279 = IC 622 Galaxy
Note that Courtney Seligman has found that Todd 20c is a star, and not -- as
I had previously supposed -- CGCG 064-091 (see the note under this number in
the "notngc" files).
I've checked that each of the sketches matches the sky as it appears on the
POSS1 prints or on the DSS. The stars were initially identified by Klaus
Wenzel; I have confirmed his identifications with one exception.
That exception is number (7). Klaus suggests that number (7) is also a star,
GSC 0268-0113, but the field around it does not match Todd's sketch with the
26-inch telescope. In addition, this star is just 2 arcmin south of IC 670
which is bright enough that Todd would have recorded it had he seen it. I
cannot find any star field that matches Todd's detailed sketch for number (7),
though his second sketch of the finder field (from 12 December 1877) pretty
closely matches the sky.
Unfortunately, his detailed field as sketched through the 26-inch is not at
the center of this finder field. His first finder field sketch from 3
December 1877 accompanying the 26-inch sketch is also unmatchable -- at least
by me -- with the sky.
Todd gives two different crude positions (11h00m, +07d10' on 3 Dec; and
11h00m, +07d17' on 12 Dec, both presumeably for the equinox of the date) for
that field center. These led me to the second finder field, but not the
first. He has several measurements of the stars in the field; you can see
these in his paper which is available at ADS (AN 113, 153, 1886). If you can
recover this object, or think that you can convince me that it is indeed
Klaus's star, please let me know. Thanks!
The remainder of the non-NGC objects are discussed in the "notngc" files.
=====
NGC 3607. See NGC 3632.
=====
NGC 3608. See NGC 3632.
=====
NGC 3609 is also NGC 3612. Steve Gottlieb noticed that Otto Struve found this
galaxy twice while searching for Comet Winnecke in the spring of 1869 at St.
Petersburg. Struve's first observation came on 16 March 1869 and clearly
refers to NGC 3609 -- but is listed in the NGC as "3612". The second
observation comes from 18 March 1869 and describes the same galaxy. The
positions are slightly different which misled both Struve and Dreyer into
thinking that Struve had seen two galaxies here, while he had in fact seen
only one.
Here are Struve's observations:
March 16 [1869]. alpha = 11h 10m 47s, delta = 27d 20m. Faint nebula about
30"-40" in diameter. Approximately 2 arcminutes north-following is a star
(10. 11), from which the nebula is in position angle 225d.
March 18 [1869]. alpha = 11h 10m 36s, delta = 27d 21m. Significantly
brighter than the previous one [NGC 3534], 20" in diameter, with evident
concentration towards the middle. Position angle from a 10th magnitude star
= 226d.
There are indeed two galaxies here, one about 25 seconds of time east of the
first. However, that second galaxy is fainter, has a lower surface
brightness, and -- in particular -- does not have the 10th-11th magnitude star
two arcminutes to the northeast.
Steve has also noticed that Struve's position for NGC 3534, mentioned in the
second observation on the same night, is offset from the true position by -13
seconds of time, close to the -15 seconds that Struve's position for NGC 3612
is offset from the true position. (The other galaxy from the same night, NGC
3563, has a position offset of only 4 seconds, but in the same direction.)
All of this makes it clear that Struve discovered the same galaxy twice. The
preferred number, by the way, is NGC 3609.
=====
NGC 3611 = NGC 3604, which see.
=====
NGC 3612 = NGC 3609, which see.
=====
NGC 3616 is probably lost. It may be one of the stars I've noted in the
position table, but I'm not sanquine about the possibility.
Found 8 April 1784 by WH, and never seen again by anyone, he published it as
merely "eF, pL; easily ver[ified with] 240[power]." The star I chose decades
ago when I was young and naive is surely not WH's object, and I am pretty sure
that the double star close to WH's place is not it, either. Neither of these
is "pretty large", and while the double star might appear somewhat nebulous on
a poor night, I don't see how WH could have seen anything but "vS" or "eS" for
it.
In the sweep, he is not much more forthcoming: "Excessively F, pL; some
doubts were removed by putting on 240. 70 (theta) Leonis f 4[m] 0[s], s 0[d]
41[arcmin]." CH's reduction to 1800 is "RA 11h 7[m] 44[s] PD 74[d]
10[arcmin]" which is very close to the position re-reduced with a modern
position and proper motion for the comparison star.
WH also had trouble with the previous class III object in the same sweep (NGC
3498, which see), though not with the immediately preceding NGC 3596 (= II
102). It's possible that the declination is off, but that would pull this
one object out of the zone of all the other nebulae found this same night. I
would rather think that the RA is out, but that, too, is a problem because of
the solidity of WH's observation with respect to NGC 3596 (Dreyer notes, "In
the sweep, it is 3.2m f, 3' s of II. 102 [= N3596], the place of which is
correct.").
Still, it's a field rich in galaxies, so we may yet dig this out. But after
examining the sweep, I am less confident than ever about that.
=====
NGC 3622. See NGC 4512.
=====
NGC 3626 is also = NGC 3632, which see.
=====
NGC 3630. See NGC 3645.
=====
NGC 3631. See NGC 3594.
=====
NGC 3632 = NGC 3626. This is an identity first suggested by Dreyer, and was
adopted by him in his notes to his 1912 edition of WH's Scientific Papers. It
is most likely correct since WH found II 30 (which later became N3632) during
one of his earlier sweeps (on 15 February 1784) when he was still perfecting
his techniques.
I did notice, however, that NGC 3599 is just 5 minutes of time preceding the
position WH gave for N3632. The problem with that galaxy, though, is that it
does not match WH's description -- "A pB nebula, it seems to contain stars; it
is of some extent" -- very well. Also, if WH had seen N3599, I would have
expected him to also record the much brighter NGC 3607 and 3608 just a minute
and a half following at essentially the same declination. He did not record
these until a month later.
All considered, then (well, all that I can think of given the field), Dreyer's
solution is the best one, so is the one that I fully endorse.
=====
NGC 3643, NGC 3644 = IC 684, and NGC 3647. Even though Marth's positions for
N3643, 3644, and 3647 are pretty good, this has not prevented later observers
from misidentifying these at one time or another. In particular, Bigourdan's
"N3647" is a star, and he labeled N3644 as "new" (his positions for both are
accurate). Thus, this latter galaxy received an IC number (684) as well as
its NGC number. Kobold got the right galaxies for N3643 and N3644, but both
he and Wirtz list N3644 as "NGC 3645(?)" (though Kobold does have an erratum
saying that though the identity is uncertain it is probably N3644). RNGC has
misidentified N3643 and N3645 (which see), and CGCG makes yet another object
in the group N3645.
Finally, just about everyone, including me, has misidentified NGC 3647. There
are four CGCG galaxies here. Most of us have chosen CGCG 039-141 -- the
easternmost -- but the brightest (by half a magnitude) of the three is CGCG
039-135, the westernmost. Steve Gottlieb has gently reminded us that brighter
objects are easier to see than fainter ones. Even with a 48-inch reflector,
Marth called this one an "eF neb *." And he saw only one object here, not
four, so the obvious choice is the brightest.
=====
NGC 3644 = IC 684, which see. Also see NGC 3643.
=====
NGC 3645. This, and five other NGC/IC objects (N3643, N3644, and N3647, which
see; and I683 and I684), lie in a relatively crowded field. There has been
considerable confusion about the identifications here because of the crowding
-- and because the NGC position of the (presumeably) brightest object, N3645,
lies in a blank area of sky a few arcminutes northwest of the group center.
This brightest object was found first by William Herschel on 23 Feb 1784. He
placed it 6m 30s preceding and 7' north of 84 (tau) Leo. The NGC position
comes from John Herschel's single uncertain observation during Sweep 143; the
object is h867 in his 1833 list, though he notes both it and h861 as being II
32. This latter object is considerably brighter than any of the galaxies in
the group, and precedes it by 1.3 min. JH saw it during two sweeps (141 and
238), but did not pick it up during Sweep 143. Similarly, h867 was seen only
during Sweep 143, but not during sweeps 141 and 238. That, combined with the
relative brightness of the object compared to those in the group and JH's
uncertain position for h867, strongly suggests that h867 = h861; i.e. N3645 =
N3630.
N3645 is also credited to Tempel who has a long discussion of the field in AN
2212 (pp.51-2). I've not translated this yet, but I do not easily see any
precise offset from a known object in the text. Is it possible that Tempel
was misled by JH's attribution of H II 32 to two different objects? A
translation is clearly needed.
=====
NGC 3646. See IC 682 = NGC 3649 where I suggest that Swift's note of a "very
faint star close north preceding" actually applies to his observation of this
galaxy. He somehow confused it with his observation of the fainter galaxy.
Curiously, WH puts this object, as well as NGC 3649 which he observed in the
same sweep, into his third ("very faint nebulae") class of objects. This is
fully three magnitudes brighter than N3649. The only reason I can see is that
the surface brightness is lower. JH has them right, though the final
"brightness" in GC and NGC ("cF") is an unsatisfactory compromise.
=====
NGC 3647. See NGC 3643.
=====
NGC 3649 = IC 682, which see.
=====
NGC 3656. See NGC 3594.
=====
NGC 3661 = IC 689, which see.
=====
NGC 3667. See IC 689.
=====
NGC 3671. WH says of this, "vF, vS; 2 vS sts in it." JH was a bit uncertain
of this faint object: "This must be my father's neb, but it is a suspicious
object, and I doubt whether it be not a little knot of 3 or 4 stars."
There is no doubt about the identification, but I think it is worth noting
that WH's two stars are the nucleus and a star just to the east. Otherwise,
this is an interesting galaxy with a bright, obviously star-like nucleus; and
a considerably disturbed, though very faint corona, with plumes. There is no
sign of an obvious companion, though. Is this perhaps the result of a merger?
=====
NGC 3674. See the entry for NGC 3683A in the "notngc" files for confusion
in the Birr Castle observations of this and NGC 3683.
=====
NGC 3676 is MCG -02-29-029. The declination given by Muller and the NGC is
about 30 arcmin too large, but the description is accurate. Muller's note, in
particular, "star 10 north-following, star 10 south-following" is correct:
each star is 0.95 arcmin from the galaxy.
=====
NGC 3677. See CGCG 242-042 which LdR probably saw; this NGC object figures in
its identification.
=====
NGC 3679 and NGC 3915 are H III 112 and III 113, both found the night of
24 April 1784, and both referred to the same star, 74 Leo (SAO 138102). There
is nothing at either position reduced from WH's offsets from this star. The
other brighter objects found on that night (N4697 and N4941 = H I 39 and 40;
and N4593, N4602, and N4989 = H II 183,4,5) were all compared with 51 Virginis
and are close enough to the derived positions to identify without problems.
JH, however, noted that Mayer 510 (SAO 138798), taken later in the same sweep,
is a better comparison star. He determined the positions of the two objects
given in GC using this star, and Dreyer adopted these positions for NGC, too.
He also discusses the problem of the comparison stars in a note to NGC, as
well as in the Notes to his 1912 edition of WH's papers. Unfortunately, there
are still no nebulae at either position.
At this point, it's worth noting that, regardless of which star is used, WH's
relative position between the two objects is the same: 24 minutes 12 seconds
in RA and 49 arcmin in Dec. This suggests that we should look for objects
matching his descriptions separated by these amounts.
Now, other observers begin to cloud the picture. Dreyer credits Peters with
an observation of N3915. But as with WH's observation, there is nothing at
Peters's position (he says that he determined it by plotting the object on
charts of his own construction). His note for N3915 reads, "AR in GC from
15 sec to 20 sec too small, and also the declination differs rather much.
The nebula is vL, and not eS, as H. III. 113 has it." Just what nebula he
saw is something of a mystery. It could have been IC 2963, but Peters's RA is
over a minute off, and his Dec is nearly 2 arcmin off as well.
Another object sometimes suggested as NGC 3915 is IC 738. However, that is
about 1m 40s and 29 arcmin off Peters's position, so seems an unlikely
candidate. There are, however a couple of galaxies that would correspond to
NGC 3679 at approximately the correct position, assuming WH's difference in
position (24min 12sec and 49 arcmin). The brighter is MCG -01-29-017, the
fainter is 2MASX J11244816-0531565. Neither, however, has a bright star
nearby that would match WH's description for NGC 3679.
Spitaler has a series of good micrometric observations of nebulae which
includes N3679. He makes it the object we now call MCG -01-29-021 = Markarian
1294. But this is nearly 15 arcmin away from the nearest of WH's positions,
and does not match his description of being "very near a very bright star."
Dreyer makes a note of Spitaler's observation in his IC1 Notes, and again in
the 1912 Scientific Papers Notes.
So, we're left with a puzzle: what did WH and Peters see? Let's assume that
WH's descriptions are good [for N3679 he says, "eF, cL, R, r (v nr vB *)"
and for N3915, "eF, eS w 240. 2 vS sts and nebulosity."]. The only objects
in the area matching these descriptions are MCG -01-29-012 (at 11 19 15.35,
-05 29 00.6; B1950.0 from GSC) which has SAO 138156 about 2 arcmin to the
north, and the previously uncatalogued galaxy at 11 44 22.20, -04 54 35.4
(again, GSC for B1950.0) which has a somewhat fainter star superposed about 15
arcsec to the southwest of its bright core. The relative positions of these
two galaxies in 1784 was 25 min 04 sec, and 35.3 arcmin, not wildly off WH's
"observed" offsets -- but not very close, either.
In the end, I've taken MCG -01-29-012 and the uncatalogued object as perhaps
the two that WH saw. It's clear, however, that there are unexplained large
errors in WH's offsets for these two objects. So, these identifications are
quite uncertain, and could well be completely wrong.
-----
In July 2016, I looked at WH's sweep. Here is what he has to say about this
object (CH's fair copy in the Herschel Archives with her reduced position for
1800 also given):
cL, excessively F, R, r; just preceding, and very near a B st. The
nebulosity touches the star. There is so much moon light that I do not see
it satisfactorily, and am, even not without some doubts as to the reality,
but must defer the verification till [sic] a darker night. Mayer's 510 p
1h 1' 48" s 1d 20' RA 11h 15' 49" PD 94d 50'
CH gives the position of Mayer's 510 as 12 17 37.1, 93 30 20 (NPD) for 1800.
This becomes 12 27 53.5, -04 36 50 for J2000 which identifies the star as
FT Vir = HD 108506. As noted above, there is nothing in WH's offset from this
star.
Going through the sweep, I see several other objects referred to HD 108506,
and I notice that the RA corrections (to WH's clock readings) for this sweep
(and the next on the same night) vary by over a minute of time from +4m 32s to
+5m 47s, with that for HD 108506 being +4m 49s. The NPD corrections also
differ with one group of five stars close to +92d 30s, and two others --
including HD 108506 -- being +93d 00s. So, WH's zero points through these
sweeps were inconsistent.
Finally, I note that he has the bright star just following the nebula and
"touching" it, while the star near MCG -01-29-012 is two arcminutes south of
SAO 138156. I would not say that the nebula "touches" the star, and the
direction certainly does not match WH's description. The star's proper motion
is small enough in both coordinates that it would not significantly change its
position relative to the galaxy over the 216 years between WH's observation
and 2000 (to which the proper motions have been reduced).
So, the puzzles remain. I'll be interested in seeing what Wolfgang has to say
about this in his evaluation of WH's observations. In the meantime, I've
changed the colon on the identification of NGC 3679 to a question mark to more
accurately reflect the uncertainty in WH's observation.
=====
NGC 3682. See NGC 4512.
=====
NGC 3683. See the entry for NGC 3683A in the "notngc" files for confusion
in the Birr Castle observations of this and NGC 3674.
=====
NGC 3684 may be H II 160. Wolfgang Steinicke has recently (2013) suggested
that WH's sweeps over this area only partially overlapped, so that he (WH)
could not have seen N3686 in the second of them (sweep 198 on 17 April 1784).
Therefore, Dreyer's suggestion that N3686 = III 28 is also H II 160, is
probably incorrect.
The equivalence with N3686 makes sense, however, given that the reduced
position from WH's observation is just 1 minute of time more and at the same
declination -- within the errors -- as the position for N3686. The difference
for N3684 is half a minute of time, and 10 minutes of arc. A mistaken reading
of a single minute of time seems more likely than errors in both RA and Dec,
but the two errors are what Wolfgang is suggesting.
Looking at CH's fair copies of the sweeps, I do not see information that can
help determine the path of the telescope on the sky, so cannot reproduce
Wolfgang's argument. The information may be in other of the Herschel Archive
files that I haven't examined yet. In particular, there is a large section
with CH's work on her brother's observations that may be quite helpful in
circumstances like these.
I have, however, re-reduced the observation of WH's nebula with all three
stars that he observed in the sweep (81, 85, and 90 Leonis), and the positions
are coincident to within WH's known errors. The problem therefore is
certainly in the observation of the nebula itself. I also see in the fair
copy that the nebula is the only one for which the time is recorded with
minutes and seconds rather than minutes and decimals. Was there something
special about this observation that WH has not told us? His full description,
by the way, reads, "cL, R, brightest in the M, but the brightness goes off
very gradually." This description could apply to either galaxy.
A not-so-by-the-way: There is no problem with the NGC identifications of
these two objects. JH adopted his own pretty good positions for them in GC,
and Dreyer adopted very similar positions for the NGC. Only the WH number,
II 160, may be wrong on the galaxies.
=====
NGC 3685 is CGCG 039-192. Though Todd's position is off (as it is for nearly
all of the nebulae he found during his search for "the trans-Neptunian
planet") his sketchs of the field are very good, as are his measurements of
distances between stars and nebulae within each field. In this case, he found
the higher surface brightness component of a pair of CGCG galaxies; the other
is UGC 6466, a pretty low surface brightness barred spiral. This is Todd's
number (9). See NGC 3604 for more about Todd's search.
=====
NGC 3686. See NGC 3684.
=====
NGC 3690 and IC 694 (which see for more discussion). These are not, as is
often supposed, the two components of the peculiar interacting system, Arp
299. Instead, NGC 3690 refers to these two peculiar galaxies, while IC 694
is the small elliptical or lenticular about an arcmin northwest. Lord Rosse
clearly resolved the two components in at least one of his observations, and
he also noted IC 694 as an "appendage" to the north-west of the pair. Swift
later rediscovered the IC object; this led Dreyer to assign it its own number
in the first IC.
Note, too, that the numbers NGC 3690 and IC 694 are incorrectly assigned to
Arp 296 in the tables in the Arp Atlas. This has further exacerbated the
naming problem, as Arp 296 is another interacting pair just a few arcmin
following Arp 299.
=====
NGC 3694. See NGC 3698 = NGC 3695.
=====
NGC 3695 = NGC 3698, which see for more. Ball's description of the field with
this, NGC 3694, and NGC 3700 is accurate. So, even though the NGC position is
off, there is no doubt about the correct identifications.
=====
NGC 3696 is probably the galaxy that I've listed in the table. It is 10
seconds, and 10 arcmin off the nominal place listed by Leavenworth. Still,
there is little besides the position to go on (Leavenworth's description could
apply to just about any of the faint galaxies in the area), so I am not
confident about the identification. There is no sketch.
Another candidate galaxy that I considered, but dropped, was NGC 3704, but
that does not have such neat offsets from the nominal position, and is
brighter than Leavenworth's description (Mag = 15.6, Size = 0.1', R, bMN)
would make it.
=====
NGC 3698 = NGC 3695. In March 1867, using LdR's 72-inch telescope, Ball found
two nebulae here forming a triangle with h899 = NGC 3694, and suspected
others. He did not measure the offsets from JH's nebula; he comments, in
fact, "There being no great difference of brightness, it is not easy to see
which is h899," but did give the relative positions of "the 2 nf ones, Pos 310
deg, Dist 339[arcsec]." These numbers are accurate for NGC 3695 and NGC 3700.
JH's position for NGC 3694 is very good, too.
Nine years later, Dreyer re-examined the field, noting that "nnp [h899] is a
pS, eeF neb [= N3695] in Pos 357.2, Dist 256.7." This is actually a star.
Dreyer goes on, "About 15' n and a few minutes f is another eF, vS neb [=
N3700] with an eF * 2' sf." This is actually a reobservation of NGC 3695,
(the star is indeed 2 arcmin southeast), though Dreyer took it to be a new
nebula and gave it a new number, NGC 3698.
The object itself has a double nucleus, easily seen in DSS2R and IR images.
The nuclear bulge on blue image suggests a peculiar amorphous bar with faint
arms. The SDSS clarifies the picture, showing two superposed spiral galaxies,
not obviously interacting -- though I suspect they are. The system is
reminiscent of NGC 3314, but considerably more distant.
=====
NGC 3700. Though the NGC position is off, Ball's description of the field,
including his measurement of the offset between this and NGC 3695, makes clear
the nebulae he found. See NGC 3698 = NGC 3695 for more.
=====
NGC 3703 is one of Ormond Stone's discoveries. He made a sketch of the field,
but it only vaguely matches the galaxy and its surrounding stars, 10 arcmin
north and 25 seconds preceding the published nominal position (the position on
the sketch is another 30 seconds on east, which puts it just a minute of time
east of the galaxy in question). In particular, the orientation of the sketch
is unusual if the identification is correct -- south is normally at the top of
the sketches; this would have south at about 10 o'clock. Also, the brightest
star shown on the sketch is actually the faintest on the sky.
In the end, this is a possible identification, but no more.
=====
NGC 3704 and 3707. This pair was found by Ainslie Common around 1880. His
position for the pair is only approximate, but his description clearly
identifies the nebulae, "2, F, R, on the parallel, star symmetrically placed
between." The star is indeed there.
The brighter object (N3704) was also seen (in 1878) by Wilhelm Tempel who
published a micrometrically measured position for it in his fifth paper on
nebulae. His descriptive note on the nebula reads, "Class III; a star 15m
(nebulous?) follows 2 sec; near the comparison star is another fainter
nebula." The star 2 sec following the measured nebula is the same one
mentioned by Common.
The positions that Dreyer adopted for NGC come from a letter to him from
Tempel. In this letter, summarized by Dreyer in a note in IC2, Tempel says
that he saw the brighter (which Dreyer mistakenly calls N3707) four times, but
the fainter only once. Further, the position of the fainter comes from a
sketch made on 25 May 1881, the same night on which Tempel measured the
brighter.
After quoting Common's description, Dreyer continues, "I assumed, perhaps
erroneously, that 3704,07 are the same as Common's, the place of which is
11h 22m 57s, 100d 33.3m [1860], though Tempel's nebulae are not on the
parallel." Dreyer's first assumption was correct, at least concerning the
brighter nebula. What is wrong, however, is Tempel's place for the fainter.
There is nothing in that position in spite of its being just about 2 arcmin
north of his comparison star, and -- presumeably -- shown in that place on
the sketch he sent to Dreyer.
My guess is that Tempel somehow confused his observations, and that his note
about the star and the fainter nebula refers to another field altogether. In
any event, Common's observation is clear enough, even if his position isn't,
to reliably assign the two numbers to the two galaxies in the field.
There is also the faint possibility that Ormond Stone saw NGC 3704; see NGC
3696 for that.
Finally, the pair may also be IC 703 and IC 704 (which see). But the case for
that is very weak.
=====
NGC 3707. See NGC 3704.
=====
NGC 3708 and NGC 3709 are lost. Seen only by Ormond Stone with the 26-inch
refractor at Leander McCormick, he gave them his usual crude positions. He
also left us a sketch of NGC 3708, showing it midway between two stars near
the edge of his field (positioned at 2 o'clock and 8 o'clock). From other
sketches with positively-identified galaxies, the field is only 6-8 arcmin
across, so the stars are separated by about that amount. There is no trace of
N3709 in the sketch. Since it is supposed to be just two arcmin south of
N3708, I wonder if it is the same galaxy, but seen on a different night.
I searched at all the reasonable digit error offsets where I've found other
"lost" Leander McCormick nebulae, but found nothing that resembles the north-
south pair in the table, nor the galaxy flanked by stars in the sketch.
So, unfortunately, two lost nebulae.
In early June 2009, Jeff Corder wrote to suggest that N3708 might be NGC 3776.
I don't think this is likely as the star field just does not match the sketch.
There turns out to be another galaxy nearby (at 11 35 20.8, -03 09 14;
B1950.0) that does have approximately equally bright stars diagonally across
the galaxy from one another. However, there are also other brighter stars
close to the field that I'd expect to be in Stone's sketch. There is a
fainter galaxy at 11 35 29.1, -03 11 30 that might be N3709 if the brighter is
taken as N3708, but one of the brighter stars I mentioned is just 1.5 arcmin
to the west-southwest. Stone could not have missed this star, and would
probably have mentioned it in his notes for N3709.
=====
NGC 3709 is lost. See NGC 3708 for the story.
=====
NGC 3711. Herbert Howe has identified this object for us. Found by F. P.
Leavenworth with the 26-inch Leander McCormick refractor, and given a
typically crude position in the second list of nebulae discovered at the
observatory, Howe must have recovered it by noting the 9th magnitude star four
arcminutes south that Leavenworth noted. Howe's position given in MN 58, 515,
1898 is a good micrometric one. With the star just where Leavenworth put it
(though there is a second, nearly equally bright star just two arcminutes
east-southeast of the first star), the identification is pretty secure.
The object itself is a pair of interacting galaxies, the southwestern a
distorted spiral, the northeastern a somewhat fainter compact elliptical or
lenticular with a distorted lens.
=====
NGC 3712 is probably NGC 3714. JH observed the objects during different
sweeps, and his position for N3712 is enough off his others to lead him to
think he'd found a new nebula. There is nothing at his position, though, and
the descriptions of his two different nebulae are very similar.
There are, however, some curiosities here. JH was looking for two of his
father's nebulae, II 367 (N3713) and III 353 (probably N3714), in the area.
JH assigned the numbers to two of his own nebulae (h906 = N3713, and h907 =
N3714), but in his description of N3713 (never seen on the same nights as
N3714), he says "No companion seen." Similarly, in his description of N3714,
he claims, "No other near on the same parallel." The two galaxies are only
12.6 arcmin apart. How does it happen that neither appeared in the same sweep
with the other -- aside from Sweep 68 where JH gives a crude declination and
no RA to h905 = N3712 -- though he went over the area in 8 different sweeps?
JH also noted the 10 minute error in his father's position for III 353. The
galaxy, however, is neither at WH's "wrong" position, nor at the "corrected"
one. (I thought I had found it just 10 seconds of time off the "wrong" one,
but I, too, made an error in RA, this one of 1 hour. Is it possible that WH
also made a 1 hour error? Nope -- in that case, the object would have
appeared preceding 44 LMi, not following it, and would have been the first
object referred to that star that night, not the last.) JH had to stretch a
bit to make III 353 fit his position, but he managed it in the note in GC,
saying that WH's position (first corrected by CH), when corrected, falls
within 35 seconds of his (JH's) own.
Finally, N3714 is a rather peculiar galaxy, having a faint, disturbed corona
with a broad plume to the southwest. I am unable to decide if two objects --
one superposed on the galaxy just to the northeast of the center, the second
32 arcseconds to the southwest -- are stars or compact companion galaxies. I
am guessing here: the superposed object is a compact galaxy, the more distant
object is a star. Based on their appearances in the SDSS image, both are
stars -- but the distortion of the big spiral is even more noticeable.
Spectra are clearly needed.
=====
NGC 3713 is probably also NGC 3927 (which see). Also see NGC 3712 = NGC 3714.
=====
NGC 3714 = NGC 3712, which see.
=====
NGC 3721, 3722, 3724, and 3730. Here is another of the Leander McCormick
fields that is irksome at best, frustrating at worst, and will probably never
be sorted out satisfactorily.
These four numbers are usually applied to various members of a group of
galaxies north of NGC 3732 (found by WH, reobserved by JH, there is no problem
with the identification of this galaxy). There is some justification for
this; the true RAs for the Leander McCormick objects are often east of the
nominal RAs, while the Decs are often (though not always!) fairly accurate.
I've listed these identifications in the big table with two question marks.
In this case, however, there is another group of galaxies to the west of
Leavenworth's nominal positions. The brightest is IC 2910. With two others,
this matches the relative positions, brightnesses, and diameters estimated by
Leavenworth for three (N3721/22/24 of the four objects (though the declination
for the northern-most, N3721, is 4 arcmin off). I've marked these candidate
objects with a single question mark.
This leaves NGC 3730, which Dreyer credits jointly to Leavenworth and A. A.
Common. I'm not convinced that they both saw the same object. If Leavenworth
saw it the same night as the other three, he rezeroed his RA because there is
no galaxy offset from the other three by the amount in his table. This
applies to both groups of galaxies, the one to the east as well as that to the
west.
Here is where we turn to Common's observation. He lists a single nebula at
the position of NGC 3732 calling it "F, R", and adds the note "... a cluster
of 3 similar ones 15' n." Dreyer, noting that Leavenworth's position is about
15 arcmin north of N3732, supposed that one of Common's "cluster" was the
object that Leavenworth saw. However, Dreyer adopted Leavenworth's RA, nearly
a full minute of time preceding N3732. He also has a note in the NGC reading
"Common has '3, F, R, 15[arcmin] n of h913 [N3732].' This is not what Common
actually wrote, of course, though it summarizes the situation pretty well.
But we are still left to wonder which galaxy to take for NGC 3730. Not quite
pulling things out of the hat, I'm going to go with the usual choice for this,
the brightest galaxy in the "cluster" north of NGC 3732. There is a question
mark on it, of course. The fainter spindle just to the south was apparently
not seen by any of the visual observers. Had it been, then the situation with
at least the number 3730 would be a lot clearer.
What about Common's other two galaxies? If the object we take as NGC 3730 is
one of his, then the other two are logically those that are sometimes called
N3722 and N3724 (those with double question marks in the table). It's not
beyond reason, though, to think that he saw those two and the third on to the
east in the line, MCG -01-30-008.
But all this is speculation. We don't have good positions from the original
observers for any of these, so all we can do is -- speculate. Frustrating,
isn't it?
-----
Yann Pothier pointed out in an email from April 2016 that the pair I've called
"NGC 3722?" and "NGC 3724 ?= IC 2910" better match Leavenworth's relative
positions for his pair than any other galaxies in the area. I take this as
another indication that these are reasonable candidates for Leavenworth's
objects.
=====
NGC 3722. See NGC 3721.
=====
NGC 3724. See NGC 3721.
=====
NGC 3726. This has a companion probably picked up by LdR in 1848. The story
is in the "notngc" files under CGCG 242-042.
=====
NGC 3730. See NGC 3721.
=====
NGC 3732. See NGC 3721.
=====
NGC 3733. See NGC 3594.
=====
NGC 3737. See NGC 3594.
=====
NGC 3738. This Magellanic irregular galaxy does not have a nucleus per se;
the short bar -- the dominant structure in the galaxy -- is covered with knots
and patches, presumeably HII regions.
The position I've adopted from GSCA is the approximate center for the entire
galaxy, and is probably about as good as we can do without picking out
individual knots.
Also see NGC 3594 where this and a few other galaxies figure in the
identification of NGC 3594 itself.
=====
NGC 3743, 3744, 3745, 3746, 3748, 3750, 3751, 3753, and 3754. The last seven
of these are Copeland's Septet. The Notes to IC1 relate how the positions in
NGC came to be calculated incorrectly. Briefly, Dreyer took Copeland's
reference to the comparison star as "reddish" to apply to the wrong star.
Thus, the differences between the NGC positions and the correct positions is a
simple offset in RA and Dec.
Here are tables showing corrected identifications and information for the
Septet area in the four major catalogues from which we drew information for
RC2: RNGC, Zwicky's CGCG, VV's MCG, and Nilson's UGC.
Here are identifications for the galaxies with objects listed in MCG, UGC, and
CGCG:
NGC MCG UGC CGCG (Vol. II, pp. 176 and 180)
3743 --- --- 11 33.2 +22 00, mp = 15.6
3744 --- --- 33.2 +23 16, mp = 15.4
3758 +04-27-073 --- 33.8 +21 52, mp = 14.8
3745 +04-28-004 --- ----
3746 +04-28-005 06597 35.1 +22 17, mp = 15.3
3748 +04-28-007 --- 35.2 +22 18, mp = 15.5
3750 +04-28-008 --- 35.3 +22 15, mp = 15.2
3751 +04-28-009 06601* ----
3753 +04-28-010 06602 -\
- 35.4 +22 16, mp = 14.6*
3754 +04-28-011 --- -/
*UGC 6601 - coordinates and magnitude wrong in UGC, but the Note clearly
points to the correct object.
*NGC 3753 are 3754 both included in the same CGCG entry.
Finally, there is a bit of a mystery concerning the name "Copeland's Septet."
When the de Vaucouleurs and I adopted this for RC2 (see Table 16b, page 52) in
the early 1970's, we thought we were following our self-imposed rule to not
provide new names for objects, but to merely copy those used in the
literature. Since that time, I've been unable to find the source of the name.
My query about this in the Webb Society Quarterly Journal (No. 90, 1992
October, page 41) has brought no response. It's possible, then, that we were
the first to use the name. Wherever it came from, it is now in common use.
=====
NGC 3744. See NGC 3743.
=====
NGC 3745. See NGC 3743.
=====
NGC 3746. See NGC 3743.
=====
NGC 3747 is H. III 969, one of the fifteen nebulae found by WH on the night of
2 April 1801, where all the positions suffer from a large, systematic error.
See NGC 3752 for more about this sweep.
=====
NGC 3748. See NGC 3743.
=====
NGC 3750. See NGC 3743.
=====
NGC 3751. See NGC 3743.
=====
NGC 3752. The night of 2 April 1801 was, as far as WH and CH were concerned,
a typical observing night. They made only one sweep that night, number 1096,
and found fifteen new nebulae in it. They also recorded four stars, but only
one had a catalogued position, 4 Draconis. The reductions were made under the
usual assumptions that the times and north polar indices could be reduced to
RA and NPD by reference to the single catalogued star, 4 Draconis.
Unfortunately, unknown to them, the telescope was not sweeping along the
meridian, but along a great circle seven degrees east of the meridian. WH did
not discover this until a few days later. Appended to his sweep of 5 April is
this note:
On examination, I find by an accident of taking down the 25 feet telescope,
my instrument has been drawn out of the meridian towards the east at least
5 or 6 degrees in azimuthe [sic], perhaps more.
He discarded the April 5th sweep, but did not realize that the same problem
affected the April 2nd sweep. The only indication he gives that something
might be wrong is this note at the end of Sweep 1096 on 2 April:
4 Draconis Hevelii as taken from Bode's Cat. (NB Woll[aston] & Bode agree)
gives 1' 46" more minus than when it was determined (in the Origional [sic]
Sweep) by 5 Draconis Hevelii of 1099 Sw; but the place from the Catalogue
appears to be the most correct, as it agrees better with another additional
star (206) [sic] Cam.) taken in that sweep; besides by 1066 and 1668 [sic;
1068 is probably meant as there is no sweep "1668"] sweeps it seems that 5
Draconis Hev. did not give so strong a correction minus, as some other
stars.
(The discarded sweep of 5 April 1801, by the way, has only 7 objects included
-- four stars, a double star, and two "vF, vS" nebulae, both confirmed with
the 300X eyepiece. There is a note at the top of this short sweep "Not to be
Numbered or registered", clearly motivated by the alignment problem. I'll
reduce this someday to find out what WH saw that night.)
In 2011-12, Wolfgang Steinicke had the opportunity to examine WH's and CH's
original records now in the possession of the RAS in London. Doing so, he
found the problem with telescope alignment, and was able to properly reduce
the observations of sweep 1096.
In the meantime, however, I had already tackled the problem and -- without
realizing its origin -- had managed to recover all of the galaxies that WH
found. Here are my original notes on the matter, with new material inserted
in square brackets. I thank Wolfgang for correspondence about this, and
answers to my subsequent questions, early in 2013. I'm also grateful to
Courtney Seligman who brought this up again in June 2015 in the context of the
identification of NGC 2938 (which see).
The problem is discussed in an article in Monthly Notices (Volume 71, pages
509-511) in 1911 where the anonymous author [possibly the Astronomer Royal
at the time, Frank Dyson; though Wolfgang has found the relevant
correspondence between the previous Astronomer Royal, William Christie, and
Dreyer] gives accurate positions for forty nebulae. These were found on
Royal Observatory, Greenwich (RGO in modern parlance) 30-inch plates
covering the area of WH's sweep 1096 on 2 April 1801. WH's positions in
that sweep are affected by a large, systematic error, so Dreyer had
requested that the Astronomer Royal have plates taken in an effort to sort
out the problems.
They largely succeeded, but the paper is incorrect in saying in a note that
h917 = N3752; actually, N3752 = H II 905. Dreyer and the article's author
correctly concluded that h917 and H II 905 are two different galaxies, but
they got the NGC number on the wrong one. The MN note should actually read
"NGC 3752 = No. 36 above = H II 905, but not h 917 = No. 38 above." This
unfortunately leaves h917 without an NGC number (see its entry in the
"notngc" files. (Following the time-honored tradition of muddying the
waters with suffixes, I suppose we could call it "NGC 3752A", but I've not
done that. Yet. I may eventually change my mind.) (But as of April 2016,
I haven't.)
Since John Herschel gave his own position, but his father's description, to
GC 2460 = NGC 3752, and since it is clear that WH saw the brighter of the
two galaxies (more on this below), the GC and NGC positions should be
changed.
To reach these conclusions, I re-reduced WH's offsets from his comparison
stars (as given by Dreyer in the Scientific Papers) [Dreyer must have seen
WH's note about the 4 Draconis problem as he identified and used the other
stars, not 4 Draconis, to calculate new offsets for the nebulae] for all the
objects in the sweep, using the SAO positions for the stars. The positions
for the nebulae so found are very poor, ranging up to almost 6 minutes of
time and 45 arcmin from the true positions. Nevertheless, there are no
other galaxies in the area of WH's positions that could match his
descriptions. By following along chronologically through the sweep, we can
be pretty sure which galaxies correspond to which numbers in WH's list (only
H III 966 = NGC 3197 is out of RA order, but its identity is clear from the
declination). This includes N3752 which, as Steve Gottlieb independently
suggested, is certainly H II 905.
Further "proof" of the correctness of these identifications comes from plots
(shown in crude form below) of the differences between WH's positions and
the true positions from the RGO plates. (By the way, I've verified the RGO
positions with modern measurements.) The differences are systematic,
increasing towards higher right ascension. Though [Dreyer] used three
different comparison stars for these observations, he used one of these,
BD +78 317, for only one object; another, BD +78 412, for two; but the
third, BD +76 393, for the remaining 12 objects. [At this point, I had a
note about Dreyer's use of the these three stars and the possible problems
that might introduce; all that is no longer relevant since I found WH's note
about 4 Draconis.] For this third star in particular, the systematic errors
are therefore quite well-determined. If corrected for these systematic
errors, WH's positions would be good to his nominal accuracy of a few
arcminutes.
To clinch this interpretation, I calculated the offset of John Herschel's
position for h917 from the true position of N3752 = H II 905. The resulting
points are coincidentally very close to the offset predicted if [Dreyer] had
used BD +78 412 as his comparison star. But, as we can see on the graph,
the points are very discrepant from the offset of the actual comparison star
BD +76 393. So, again, N3752 is almost certainly II 905 and not h917.
Here is a list of the galaxies from the 1911 MNRAS paper, along with the NGC
numbers, the numbers assigned by other observers, and the differences
between WH's positions and the RGO positions. The objects flagged with
asterisks are those found by WH during sweep 1096.
MN NGC WH Others Delta RA Delta Dec
(WH - RGO)
1* 2938 III 963 [h 612, a star] -1m 54s -17.8 arcmin
3* 2977 I 282 -3 17 -17.5
6* 3061 II 903 [h 653, not found] -1 49 -14.3
7* 3197 III 966 +1 34 + 6.9
8* 3144=3174 III 964 d'Arrest -2 16 - 2.1
9* 3155=3194 III 965 h 676, d'Arrest -1 53 - 0.9
11* 3183=3218 I 283 d'Arrest -2 25 + 1.2
13 3252 III 316 --- ---
15* 3329=3397 I 284 h 733 +4 01 +26.6
25 3403 II 335 h 767 --- ---
27* 3465 III 967 h 795 [h 802, n.f.] +0 50 +11.4
29* 3500 III 968 -1 33 +10.7
30* 3523 II 904 +1 12 + 9.9
34 3538 ... d'Arrest --- ---
36* 3752 II 905 +2 29 +14.8
37* 3747 III 969 +1 51 +12.7
38 .... ... [h 917, a star] (+5 22 +39.1)
39* 3901 III 970 +5 40 +42.9
40* 3890=3939 III 971 H III 940, d'Arrest +1 43 +25.3
Finally, here is a crude representation of the plot of the position
differences, taken in the sense WH minus RGO:
Delta Dec
(arcmin)
-- + Comparison stars used
* = BD +76 393
+40 -- (*) N3752 if h 917 + = BD +78 412
x = BD +78 317
--
+30 --
-- * +
+20 --
-- * N3752 if II 905
*
+10 -- ***
x
--
*
0 -- *
*
--
-10 --
-- *
-20 -- * *
| | | | | | |
12h 11h30m 11h 10h30m 10h 9h30m 9h
RA
Delta RA
(minutes)
+6 --
+
+5 -- (*) N3752 if h 917
+4 -- +
+3 --
* N3752 if II 905
+2 -- *
* x
+1 -- * *
0 --
-1 --
*
-2 -- * * *
* *
-3 --
*
-4 --
| | | | | | |
12h 11h30m 11h 10h30m 10h 9h30m 9h
RA
=====
NGC 3753. See NGC 3743.
=====
NGC 3754. See NGC 3743.
=====
NGC 3756. See NGC 3594.
=====
NGC 3758. See NGC 3743.
=====
NGC 3760 = NGC 3301. As with N3575 = N3162 (which see), d'Arrest's RA is 1
hour too large (he measured both on the same night, 21 February 1863). In
addition, his note "* 10-11 p 4.0 sec, 175'' south" should place the star
north of the galaxy, not south. With these two changes, his single
observation of his "nova" is in perfect accord with his three observations
of NGC 3301.
Dreyer notes (in the NGC Notes) Copeland's not finding the object at Birr,
discovering instead "a large group of novae preceding it" (Copeland's
Septet, which see under NGC 3743). He further comments in IC1 that the
Strassburg observer (Kobold, who apparently first suggested the equality with
N3301) also could not find N3760.
=====
NGC 3763 = IC 714. For once, the Leander McCormick observation, this one a
micrometric one by Francis Leavenworth, referred to an unmistakeable star, is
correct (though perhaps with a 10-arcsec declination error). Even A. A.
Common's position is fairly close, only 12 seconds of time and one arcminute
off.
So Dreyer must have been feeling cautious when he did not mention that the two
entries might refer to the same object -- or perhaps he just missed them.
Leavenworth does list his comparison star as "Wash. Cat. 4946" -- it is theta
Crateris with a V magnitude of 4.7 -- so it would not be instantly
recognizeable to someone reading through the list of Leander McCormick
observations. Also, Common has an odd note about it (at least I suppose his
note refers to the star.) His full description reads "F, diffused, sp 7
stars." The galaxy is indeed "sp", but what does "7 stars" mean? I don't see
any other galaxy in the area that has seven obvious stars to the northeast, so
given that Common's position is not all that bad, I'll leave this particular
mystery to someone else to solve. Perhaps an eyepiece view with the same
power and field as Common used on his 36-inch would be more revealing than the
DSS.
=====
NGC 3764. This, as noted in CGCG and MCG, is part of a double system; only
the eastern component is bright enough that d'A could have seen it. Somewhat
unusually, the two galaxies have quite different types. The western object is
a late-type spiral, perhaps an SBd III-IV with pretty low surface brightness.
(What, at first sight, appears to be a knot on its northern edge, is probably a
background galaxy; the SDSS spectrum confirms this). The brighter eastern
galaxy is an S0 (or perhaps an elliptical).
There hardly appears to be any interaction between the two, though the
redshifts reported by NED are similar (given that they come from different
sources, it's possible that they both refer to the brighter eastern object).
Another obvious nearby galaxy is on to the east by a few arcminutes; it, too,
is well in the background given its SDSS spectrum.
=====
NGC 3769. One of the nearby galaxies is often called "NGC 3769A" following
its entry in Holmberg's 1937 list of double and multiple galaxies. However,
it was first seen by LdR in 1852 with his 72-inch reflector at Birr Castle.
See the entry for NGC 3769A in the "notngc" files for the full story.
=====
NGC 3771. My previous note on this was not very helpful, so here is a better
one. This is another of the Leander McCormick objects found by Leavenworth
with very poor discovery positions. In this case, Leavenworth's position is
about 1m 40s west of a galaxy that matches his description (m = 14.5, diameter
= 0.1 arcmin, round), with a star of the appropriate magnitude (10) preceding
15 seconds of time. The galaxy is the brightest of a group.
As I've noted several times here, the LM positions are often fairly good in
declination, but well off in RA. This appears to be the case here, so I've
adopted the identification, though with some uncertainty.
=====
NGC 3774. Amazingly, Leavenworth's position is pretty good for this barred
spiral. Furthermore, his description has the bar in the correct position
angle, though his note about a 9th magnitude star 3 arcmin "np" is wrong --
the star is "sp", that is southwest, not northwest. But most everything else
matches up well enough that I have little doubt that this is the galaxy that
Leavenworth saw at Leander McCormick. In particular, his sketch matches the
sky pretty well.
Curiously, that sketch includes, in Leavenworth's note "another neb or eF *
p 0.5[arcmin]". The sketch shows it closer to the bar than that, so I wonder
if he didn't glimpse the bright patch that actually defines the southwestern
end of the bar. Another option, of course, is that he noticed a supernova.
In that case, the date of the sketch, "Feb 7 [18]87" is worth noting.
=====
NGC 3775. See both numbers: NGC 3779 = IC 717.
=====
NGC 3776. See NGC 3708.
=====
NGC 3779 = IC 717, which also see. A. A. Common found this sometime in 1880
along with NGC 3775. He gives a position for N3775, but notes this as only
"... another 5' nf, eeF." Dreyer either concocted a position for the object
from Common's published information, or asked Common to provide one. I
suspect the latter because the NGC position is given with the usual precision
that Dreyer adopts for other of Common's nebulae (see NGC 3858 = NGC 3866 for
a case where this usual precision is not used). That position is not all that
bad as it turns out.
Unfortunately, Frank Muller only measured a right ascension for the galaxy,
and that is marred by what I think is a transcription error (see the IC 717
note for more), but his description fits the galaxy perfectly. So, the
identification with IC 717 is certain in spite of the missing declination and
the bad RA.
The identity of the two numbers was first suggested by Herbert Howe in 1899.
Curiously, his position is just one arcminute too far north, one of the few
times that we find an error in his work. I wonder if this, too, is due to a
transcription error. Howe also "... suspected another [nebula] between it
[N3779] and 3775." But this is only a faint star; it would have been near the
limit of his 20-inch refractor.
=====
NGC 3780. See NGC 3594.
=====
NGC 3786. See NGC 3793.
=====
NGC 3788. See NGC 3793.
=====
NGC 3789 is much more likely to be MCG -01-30-015 than MCG -01-30-019. The
western galaxy is much brighter, and Leavenworth's description matches the bar
(which extends north-south) very well. The eastern galaxy is considerably
fainter, almost round, and has a fainter companion about 30 arcsec west. Had
Leavenworth seen this pair, he would more likely have described it as extended
east-west.
It's true that Leavenworth's position is closer to MCG -01-30-019 than to
-015. However, his position is about 1.5 minutes east of -015, an error that
many other of his observations share.
=====
NGC 3790. See NGC 3807.
=====
NGC 3792 is probably the double star listed in the table. Holden has two
observations of it, noting in the second that the "Neb makes an isosceles
triangle with DM 2523 and 2525." The only likely object making that triangle
with the two BD stars is the double.
=====
NGC 3793 and NGC 3797 are most probably stars. Tempel has this to say about
them in his paper in AN 2439 (1882): "For the fine double nebula [GC] 2479-80
= h. 331-32 [should be 'h. 931-32' = N3786,8], I have one hasty sketch from 12
Febr. '82, which shows two very small nebulae +18 sec and +30 sec following
the southern component [of the double nebula], which I cannot find
catalogued." (He goes on to describe his observations of NGC 3786 and 3788.)
There are two 15th magnitude stars at the appropriate offsets in RA, just a
minute or two south of the declination of the brighter galaxies.
For the NGC, Dreyer placed Tempel's two novae following the northern
component, NGC 3788. This makes the RA's of the novae too large by 2-3
seconds, and displaces the positions well off the stars. This has misled RNGC
to assign NGC 3793 to the much fainter galaxy VV 575 = CGCG 157-007 south-
preceding NGC 3786,8. When the correct reference galaxy is used, the RA's
come to within a second or two of the stars. Thus, these are almost certainly
the objects that Tempel saw.
=====
NGC 3794 = NGC 3804. There is no doubt that the objects are identical.
Herschel's positions are 30 seconds of time apart, his descriptions are
similar, and there is no galaxy at the position of NGC 3794. The RNGC got the
wrong galaxy for NGC 3794, supposing that Herschel made a 1 degree error in
the declination as well as a 1 minute error in RA. It is more likely that
WH made a single smaller error rather than two larger ones.
See NGC 3594 where the errors in WH's position for NGC 3804 can be explained.
=====
NGC 3797. See NGC 3793.
=====
NGC 3801. Steve Gottlieb suggests that WH saw this brighter of the pair --
NGC 3802 is the fainter -- twice, so that H III 30 = H II 161 = h 939 = GC
2490 = NGC 3801. This leaves JH as the sole discoverer of NGC 3802. See also
NGC 3807 where this figures in observations by LdR.
=====
NGC 3802. As I note above with NGC 3801, Steve Gottlieb suggests that WH saw
only that galaxy in his two sweeps in the spring of 1784, rather than this
fainter object in one of the sweeps (14 March) and the brighter object in the
other (17 April). This does not change the NGC identifications of either
galaxy, just their discovery history.
Wolfgang suggests that WH missed seeing NGC 3802 because he was using the
optically-inferior Newtonian focus of his telescope (he did not change to the
Herschelian focus until September of 1786). This raised his limiting
magnitude by about 0.5, enough to insure that NGC 3802 remained undetected
until JH -- using the Herschelian focus from the beginning of his observations
-- came across it in March of 1827.
See NGC 3801 for a bit more on this, and NGC 3807 where this figures in LdR's
observations of the area.
=====
NGC 3803. See NGC 3807.
=====
NGC 3804. See NGC 3794.
=====
NGC 3806. See NGC 3807.
=====
NGC 3807 is a star, identified on LdR's diagram (it is labeled "C"). Steve
Gottlieb has convinced me (April 2010) that Bob Erdmann and I got the wrong
star when we went over the field a few years ago. The one Steve favors is
correctly situated to be the object shown on LdR's diagram, while the somewhat
brighter star that Bob and I had picked out earlier is nearly a full minute of
time on further east. That would place it well off the diagram, so it is
almost certainly not the object that LdR and his observer saw.
Other nebulae also shown on the diagram are N3790, N3801-03, and N3806, the
first three observed by the Herschels, the last also seen by d'Arrest.
=====
NGC 3810. See NGC 4368.
=====
NGC 3817. See NGC 3848.
=====
NGC 3819. See NGC 3848.
=====
NGC 3820. See NGC 3848.
=====
NGC 3822 = NGC 3848, which see.
=====
NGC 3823. JH has a note in CGH that reads "It is just possible that by a
double mistake of 1m in RA, and 1[deg] in PD, this nebula may be h 957 [NGC
3831]. Both observations are correctly reduced."
In fact, there are two galaxies matching JH's descriptions close to his
positions, so we can be reasonably certain that he did in fact see and measure
the two with no errors in his reductions.
=====
NGC 3824. See NGC 3594.
=====
NGC 3825 = NGC 3852. See NGC 3848.
=====
NGC 3826 = NGC 3830, which see.
=====
NGC 3828. The NGC position is within a minute of arc of the GSC position.
Also, Bigourdan's original position, if reduced with respect to the GSC
position for his comparison star, is within 3 arcsec. So how did CGCG -- and
by extension, UGC -- miss the identification? Perhaps a mistake in precessing
the position? In any event, the identification needs to be added to CGCG
1140.4+1646. The UGC Notes for UGC 6686 (6 arcmin east of NGC 3828) give data
for the NGC galaxy, but only under the CGCG number. These notes, too, should
have the NGC identification added.
=====
NGC 3829. See NGC 3594.
=====
NGC 3831. See NGC 3823.
=====
NGC 3833. See NGC 3848.
=====
NGC 3830 is probably the same galaxy as NGC 3826. The only observer to see
N3830 (= h956) was John Herschel -- and his one observation is doubtful. His
description reads (in full): "Cloudy; hardly discernable." This is from
Sweep 416 of 19 April 1832.
JH's position for N3830 follows that for NGC 3826 (= H II 341 = h954) by 43
seconds of time; the declinations are identical. In addition, N3826 was seen
during three sweeps (115, 343, and 417), all different from the single sweep
during which N3830 was found. JH's three positions for N3826 are all in
agreement.
My guess is that because of the clouds, JH did not zero Sweep 416 on stars as
well as he usually did. This half-baked idea could be checked by comparing
JH's RA's for other objects in the same sweep with modern RA's: are they also
off in RA by about 40 arcsec of time? See NGC 898 where this sort of error
has undoubtedly been made. Another, probably more correct guess, is that JH
simply made an error in the RA.
=====
NGC 3841. See CGCG 097-087 in the "notngc" files; the CGCG galaxy was
mistaken for NGC 3841 by Bigourdan.
=====
NGC 3842 is the brightest galaxy in Abell 1367. See CGCG 097-087 for some of
Bigourdan's work in the cluster, and comments about others of his discoveries.
=====
NGC 3847 is just where JH put it, in spite of the note in IC2. Wolf chose the
wrong galaxy for N3847 (his object is actually IC 2952); coincidentally, the
difference in declinations is just 10 arcmin. See also NGC 3855 where I
suggest that this galaxy might also be NGC 3856.
=====
NGC 3848 is probably NGC 3822, and NGC 3852 is probably NGC 3825. The
two questionable identifications are a pair found by William Herschel on 15
March 1784, III 35 and III 36. He describes them as "Two on parallel, 3 or 4
arcmin distant. Both eF, vS," and assigns a single position to the pair.
Dreyer, in the Notes to his 1912 edition of WH's papers, claims for N3848,
"Observed by Bigourdan, place correct." For N3852, he says, "RA possibly 1
minute too great (see II 64 [NGC 4352]). Not found by Bigourdan."
This is curious, as Bigourdan clearly states "Not seen, at least in a sure
way" for N3848, and "Not seen" for N3852. Perhaps there is a note in one
of Bigourdan's Comptes Rendus papers. In any case, Bigourdan has precise
measurements for NGC 3822 and NGC 3825, and identifies them correctly. They
are 2 minutes west (not 1 minute) of WH's positions for N3848 and N3852, and
they match WH's description well.
Other fainter galaxies in the area include NGC 3817, 3819, 3820, 3833, and
several CGCG/MCG objects. Since N3822 and N3825 are the brightest of the lot,
they are most probably the ones that WH picked up.
Incidentally, the five brightest of the galaxies (NGC 3822, 3825, 3817, 3819,
and 3820, in order of descending brightness) form Hickson's compact group
number 58. The group is in the foreground of a very rich distant field of
galaxies, well seen in the red DSS2 image.
=====
NGC 3849 = IC 730. Todd's sketches [this is his number (10)] from 14 Dec 1877
positively identify the galaxy, though his position (read from the setting
circles of the Naval Observatory's 26-inch refractor) is -- as usual -- well
off. In spite of his poor position, he was able to recover the object on 11
Feb 1878, and changed his description of it from "large and nebulous" to
"small, quite condensed, somewhat nebulous, and faint." See NGC 3604 for more
about the nebulae that Todd found.
The galaxy was rediscovered by Javelle about 15 years later. Aside from the
uncertainty in the position (from the BD) of his comparison star, Javelle's
position for the galaxy is very good. His description (with the 30-inch
refractor at Nice) is accordant with Todd's second observation.
=====
NGC 3850. See NGC 3594.
=====
NGC 3852 = NGC 3825. See NGC 3848.
=====
NGC 3853. Wolfgang Steinicke has suggested that this galaxy was actually
discovered by WH on 30 December 1783, early in WH's amazing first year of
sweeping the sky with his 20-foot reflector. WH says of it (from CH's fair
copy in the Herschel Archives):
Some minutes after 32 [clock time] I saw a S Neb. but in looking a good
while at the finder to determine is [sic] place lost it again. I suspect
partly that it only consisted of a few vS st. but shall look for it another
night. 95 (o) Leonis f .... n 0[deg] 54[arcmin] RA 11h 3[min]:: .. PD
72[deg] 20[arcmin].
It never made it into WH's catalogues, probably because of the uncertain RA.
He certainly never recorded it again, so probably did not search for it as he
said he would.
There are only three objects in the sweep: this one, 95 Leo, and NGC 4028
(which see). Unfortunately, WH did not record a time for the transit of the
star (or the first nebula), so had no way to reduce the right ascensions of
the two nebulae. He managed to find an approximate position for NGC 4028
using the clock correction from the previous sweep on the same night, but with
no time recorded for this nebula, only an approximate RA could be deduced --
and it is well off the true value which should be 11 34 06, 72 20. However,
the declinations for all three objects are correct, and the objects at least
occur in the sweep in the same order as they appear on the sky.
It was left to Alphonse Borelly to rediscover NGC 3853 in 1872 (and he
measured it micrometrically), so he is its sole observer credited by Dreyer in
the NGC.
=====
NGC 3854 = NGC 3865. Here is another case where neither discovery position is
particularly good. Common's is his usual estimate, while Leavenworth's RA is,
as usual, just bad. Leavenworth also, rather unusually, has a 10 arcmin Dec
error as well for this galaxy. Unfortunately, there is no surviving sketch.
But there is still no mistaking the object. His description is appropriate
for the brighter central part of the galaxy, and his estimate of the position
angle (70 degrees) is not too far off. Finally, he has another nebula in the
correct relative position (assuming the 10 arcmin error is fixed), and that
nebula (N3858 = N3866, which see) also bears an appropriate description.
Finally, while Brian suggested that the object he measured the position for is
the "brighter of two merged", the second object looks very much like a
superposed star on the DSS2 and 2MASS images. However, Allan Sandage, in the
Carnegie Atlas, agrees with Brian. Radial velocities will tell us for sure.
=====
NGC 3855 may be IC 2953 and NGC 3856 may be NGC 3847. These were both found
by d'A. Unfortunately, he provides only a crude position for the first; the
second is mentioned only in his description, with not even an offset given.
Dreyer concocted the position in the GC Supplement and the NGC from the scanty
information that d'A has in his description of N3855.
So, there have been several guesses made at the identities by Wolf, Spitaler,
CGCG, and RNGC. I think they are all wrong, and that d'A probably saw IC 2953
and NGC 3847. These are the brightest galaxies in the area, so would be the
ones most likely seen during a hurried observation.
However, this too is a guess -- a better one, I think -- but still a guess.
=====
NGC 3856 may be NGC 3847. See NGC 3855 for the story.
=====
NGC 3858 = NGC 3866 is the southeastern of a pair of big spirals, both with
relatively low surface brightnesses. I'm a bit surprised the Herschel's
missed them; both have many other galaxies that are considerably fainter.
In any event, A. A. Common found both objects, but gave a position for only
the brighter northwestern. For this one, he says only "... another sf not so
L." Dreyer rounded off the RA to a full minute of time, and put a plus-minus
sign on the NPD. But once we've identified the brighter object -- it is N3854
= N3865, which see -- this one falls into place, too.
For this one, Leavenworth has his usual approximately correct declination, and
his usual sloppy RA. But his description is very good for the central part of
the galaxy, and he mentions the "* 9.5, p 3 seconds." There is no doubt about
the identification.
=====
NGC 3862 is not IC 2955. Bigourdan saw and measured both on the same nights,
so the two numbers cannot refer to the same object.
=====
NGC 3865 = NGC 3854, which see.
=====
NGC 3866 = NGC 3858, which see.
=====
NGC 3871 = IC 2959 is an edgewise Sa or Sab, the western-most of a group of
four first seen by JH in April of 1827. Curiously, he saw only three of the
four then, those forming "... an unequally divided line of 3." These three
are NGC 3878, 3880, and 3881. Four years later in April of 1831, he saw "...
3 forming an equilateral triangle." These three are NGC 3871, 3880, and 3881.
Considering the extremely crude positions he measured in 1831 (given to only
a full minute of time, and a full arcmin, all marked +- with the exception of
the NPD for NGC 3880), he sorted out the area remarkably well, recoginizing
that he had actually seen all four of the brighter galaxies here.
Fortunately, his earlier positions are very good so led not just him, but
later micrometric observers to the correct objects. Spitaler saw all four in
1892 and measured positions for three of them.
In March 1856, Lord Rosse saw only the three forming the equilateral triangle,
so Dreyer was understandably puzzled by JH's note for N3871: "1 minute added
to the R.A.; it is evidently the first of the group of 4."
In any event, the confusion was sorted out in time for a clarifying note in
the first IC. Unfortunately, Javelle seems to have not seen that, so N3871
picked up an IC number in IC2 from his observation in June of 1896.
=====
NGC 3873 and NGC 3875 Steve Gottlieb notes that there is some confusion in
the NGC concerning WH's number: It actually belongs on NGC 3873. The note
"III 387 sf" should also be transferred to NGC 3875 where it will read "III
387 np". The confusion arose because of a comment d'A made in his
description of NGC 3875: "Double nebula H. III. 387 follows to the south."
This may be a mistranslation of d'A's Latin text; if so, then Dreyer made the
same mistake!
The NGC identifications are not affected.
=====
NGC 3874 is probably the double star that Reinmuth noted. WH's position is
close following the double, and his description "vF, vS, left doubtful.
Twilight" is appropriate. Dreyer notes that Bigourdan did not find the
nebula; Bigourdan searched unsuccessfully for it twice.
=====
NGC 3875. See NGC 3873.
=====
NGC 3878. See NGC 3871 = IC 2959.
=====
NGC 3880. See NGC 3871 = IC 2959.
=====
NGC 3881. See NGC 3871 = IC 2959.
=====
NGC 3888. See NGC 3594 and NGC 3889.
=====
NGC 3889. The NGC has this as 5' south of NGC 3888. This is incorrect; the
original observation by Lord Rosse in 1852 places the nebula 5' north of NGC
3888. Of the three galaxies there, I've taken the brightest as N3889.
[Note added June 1999: My old friend Tom DeMary has pointed out that the
brief explanation above might not be enough to cover the situation. Here is a
fuller story.]
Lord Rosse's original observation of NGC 3888 in 1852 has a second nebula five
arcmin north (he most likely saw the brightest of the three galaxies north and
northeast, so that is the one I've taken). In 1878, Dreyer revisited the
field, but found nothing to the north. Instead, he measured an object at a
position angle of 167.5 deg with a distance of 340.5 arcsec from N3888. It
was this measurement that led to the position and note in NGC for N3889.
Using the DSS position for NGC 3888, Dreyer's measurement reduces to
11 45 03.36, +56 09 09.3.
There is nothing at Dreyer's measured position. However, if he made a
transcription error in his distance -- read 240.5 for 340.5 -- then his
position falls close to a faint star (his position is 11 45 00.81,
+56 10 47.0 for B1950.0; the star is at [end figures only] 01.51 and 52.6).
It seems likely that this is the object that he measured and mistook as the
nebula seen by Lord Rosse.
=====
NGC 3890 = NGC 3939, which see.
=====
NGC 3898. See NGC 3594.
=====
NGC 3899 = NGC 3912. Though JH's position falls close to a very close double
star (merged on POSS1), it is more likely that his observation refers to NGC
3912. His descriptions are the same, and his position for N3899 is just 1
minute of time west of N3912. Reinmuth first suggested the identity.
=====
NGC 3901. This is one of fifteen nebulae found by WH on the night of 2 April
1801 which have positions affected by a large, systematic error. See NGC 3752
for more.
=====
NGC 3905. Is this also possibly IC 2962 (which see)? I doubt it.
=====
NGC 3908. Though Swift describes his object as "F, vS, R, mbM," I have my
doubts that he could have seen the galaxy listed in the table. At 16th
magnitude, it is too faint to have been included in CGCG, and it is not large
enough to have captured VV's attention when he was compiling MCG.
Still, there is nothing else in the area, or at reasonable digit errors, that
Swift might have seen. The only other object Swift found the same night
(10 April 1885) was NGC 5304. That shares an RA offset with NGC 3908 (-15
arcsec for N5304, -13 arcsec for N3908), but the declination of N5304 is just
1.4 arcmin off, essentially perfect agreement for Swift.
So, the faint elliptical is as good a guess as any as to which object Swift
actually saw, but visual verification would be nice.
=====
NGC 3909 is a very large scattered group of fifty to sixty pretty bright
stars; I'm not sure that it is a real cluster, however. JH took as its
position one of two double stars which he saw in it. The same double served
as the source of Brian Skiff's position, too.
However, ESO's position, on to the east another 38 seconds of time, is more
appropriate for the apparent center of group. ESO made its dimensions roughly
20 by 15 arcmin, but I measure it to be 24 x 14 arcmin.
Coincidentally close to the center, and shining right through, is
ESO 217-G007, a small Sa or Sb galaxy.
=====
NGC 3911 is the brighter and following of two galaxies (the other is NGC
3920). It was found by WH whose position is very good. JH also saw it, but
because his RA was off, thought it a nova and noted, "Follows III 341 [N3911]
on same parallel." The galaxy he thought to be his father's was actually the
nova, however. Since JH's RA is about 45 seconds too far east, this, and his
note, have confused the identifications of the two objects ever since.
Neither d'A nor Dreyer found a nebula at JH's position, of course. In spite
of the correct NGC position for N3911, most modern catalogues place the two in
numerical order. This necessitates changing the RA's of both.
In placing NGC 3911 on the following galaxy, I am giving precedence to the
historical order of discovery, attributing to WH the brighter galaxy he
actually saw. Since JH was the first to see the fainter preceding object, the
number NGC 3920 given by Dreyer to h 996 (JH's nova) necessarily applies to
it. This leaves the numbers out of RA order, and also disagrees with the NGC
notes about which is preceding and following, but better represents the
history in this case.
=====
NGC 3912 = NGC 3899, which see.
=====
NGC 3913 = IC 740. WH's RA is just far enough off (14 seconds of time) that
neither Swift nor Dreyer recognized Swift's 33rd object in his 9th list as
being a reobservation of WH's object. Swift's position is just 6 seconds off
in RA, so being as far north as it is, the galaxy is unambiguously identified.
See NGC 3594 for more on the source of WH's RA error.
=====
NGC 3915. See NGC 3679.
=====
NGC 3916. See NGC 3594.
=====
NGC 3920. See NGC 3911.
=====
NGC 3921. See NGC 3594.
=====
NGC 3922 = NGC 3924, which see.
=====
NGC 3924 = NGC 3922. "Both" objects were discovered by William Herschel,
but the positions that he gave them were rather discordant. He found N3922 =
H III 716 on 9 March 1788, and placed it at 11 48.5, +50 29. N3924 = H II 825
was placed at 11 51.1, +50 33 (1950) by its discovery observation on 8 March
1789. But the next year (17 March 1790), Herschel redetermined its position
and found 11 48.9, +50 28. Within Herschel's usual errors, this position is
identical with that for III 716. Dreyer realized the identity when he was
preparing his edition of William Herschel's Scientific Papers which he
collected and published in 1912. He also has a brief note about it in MNRAS
73, 37, 1912.
I think the NGC positions come from d'Arrest or Tempel, but haven't chased
them down yet. Dreyer also has an intriguing note on the pair in the NGC
itself: Tempel apparently saw two nebulae here, though d'Arrest picked up
only the brightest.
The confusion in the current catalogues comes from both CGCG and MCG which
identify both numbers differently. There are many faint galaxies in the area
(which is right in the plane of the Local Supercluster, and in the heart of
the Ursa Major Cloud), but only one with a surface brightness high enough to
be picked up easily at the eyepiece. This is the one that Herschel observed
at least three times, and can be confidently called "NGC 3922 = NGC 3924."
This is MCG +08-22-017 = UGC 6824. Though CGCG and UGC put the number N3924
on UGC 6849 = MCG +08-22-026, this is a low surface brightness galaxy that
Herschel probably would not have noticed while sweeping. (Could this be
Tempel's second nebula, though? I'll have to check.) Unfortunately, UGC,
RNGC, and RC3 copied CGCG's incorrect identification for UGC 6849.
=====
NGC 3926. It's not quite clear which of these two galaxies is the one that
the Herschels saw. WH might actually have glimpsed both. He writes, "vF, vS,
lE, er or S patch of sts." JH, too, may have seen both: "eF, R, S, near a
star." The nearest star is over three arcminutes away (to the northwest), so
I think that JH's "star" may have been the second galaxy.
It is logical to suppose that the primary nebula seen by the Herschels is the
brighter of the pair. So, this is how I have relabeled the objects when I
looked at them again in February 2015. The A/B suffixes come from RNGC.
=====
NGC 3927 is probably NGC 3713. D'A has only one observation of it, and his
comment reads, "Satis pallida; modicae magnitudinis. Observatio haud dubia,
[c]oelum vero non favebat. Defesso caeteroquin oculo et hebetato." (My
translation with the help of Google Translate: "Quite faint, medium size.
While there is no doubting the observation, the sky was not favorable. Tired
and dull eye, too." Someone who knows Latin can probably do better.) Given
that, it's perhaps not strange that there is nothing at all at his position.
While I checked at positions resulting from a few digit errors, Steve Gottlieb
found NGC 3713 at the correct declination just 20 minutes of time preceding
d'A's position. We're reasonably confident that this is the correct galaxy,
but I've still put colons on the number as a flag.
=====
NGC 3928 may well be the faintest galaxy known with well-developed spiral
structure. See Sidney van den Bergh's short article and splendid photograph
in PASP 92, 409, 1980. Also see NGC 3932.
=====
NGC 3931. WH's RA is 1 minute too large. This was first mentioned, as far as
I can determine, by Anders Reiz in his thesis published in the Lund Annals,
No. 9, in 1941.
Reinmuth took a much fainter galaxy closer to WH's position as N3931. But
even though it is a high-surface-brightness object, it is quite faint and very
small. If WH could have seen it, I think he would have simply counted it as a
star. Perhaps a visual investigation is in order, but this galaxy is so much
fainter than the one just a minute of time preceding, that I think that Reiz
must have chosen the correct object.
Here is a curious footnote. Dreyer reports in his 1912 notes to WH's lists
that Bigourdan could not find NGC 3931. However, looking at Bigourdan's big
published table, we find a "Nova" as the very next object following his entry
for NGC 3931. He found it the same night that he searched for N3931.
Bigourdan did not include this new nebula in any of his lists of new objects,
so it has no IC number. Reducing this observation, however, shows that it
refers to the very object that Reiz picked up 40 years later.
Finally, the number "NGC 3917A" is sometimes put on this object. This was
first done by Philip Keenan in a 1935 paper (ApJ 82, 62); I've copied the
number only to make it clear which galaxy Keenan actually listed. Let's not
carry this any further, shall we?
=====
NGC 3932 is a star. D'A has only one observation of it included in his AN
1500 list (where it is No. 125), and in the shorter list (where it is No. 84)
that he sent to JH for inclusion in GC (where the NPD is 6 arcsec larger than
the NGC NPD). He chose to not include it in his big 2nd monograph; Wolfgang
suggests that this was because d'A knew it was a star by that time.
In the AN list, d'A describes it as "vF, S. Companion of h. 999 [N3928],"
while in the GC, the description reads "vF, v diffic, H.II.740 np." JH is
surely responsible for substituting his father's catalogue number for his own,
but I suspect that the "v diffic" comes from d'A. I would guess that d'A
prepared the two lists at different times from the same observing logs.
Perhaps the logs have both "S" and "v diffic" in them.
In any event, the faint galaxy chosen by CGCG is not d'A's object -- it is 17
arcmin off his position, and is probably too faint for him to have seen with
his 11-inch refractor.
RC1 got it right: In the note for NGC 3928, the de Vaucouleurs say "NGC 3932
sf 5.5 arcmin is a star." They also have a reference to Reinmuth (1926, "Die
Herschel-Nebel", in Vol. 9 of the Heidelberg publications) who gave the NGC
position (d'Arrest's), a diameter of 0.3? x 0.3? arcmin, and the description
"* 11.0 in eeF neb?" Reinmuth also classified the object as "(c)" on Wolf's
system -- this means a star (or stellar nucleus) surrounded by a corona of
faint nebulosity. There is, however, no trace of nebulosity surrounding the
star on POSS1 or on POSS2.
=====
NGC 3933 and NGC 3934. Dreyer credits these two galaxies only to Borelly, but
they were independently discovered by Pechule. I suspect that he does not
list Pechule as the positions for the five galaxies in Pechules paper are
only estimates from the BD charts while Borelly measured his micrometrically.
See NGC 4239 for more about Pechule's discoveries.
=====
NGC 3937. See NGC 4055 and IC 2968.
=====
NGC 3939 = NGC 3890. This was identified on a plate taken at RGO at Dreyer's
request to sort out WH's positions during his sweep 1096 on 2 April 1801; the
results were published in MN 71, 509, 1911. Dreyer then labeled III 971 in
his 1912 collection of WH's papers as NGC 3890. Curiously, he mentions N3890
in his 1912 MN note giving NGC corrections, but not N3939. See NGC 3752 for
more information.
=====
NGC 3948 is a star identified precisely by Bigourdan's one measurement in
1886. The RNGC identification with N3954 is wrong.
=====
NGC 3949. See NGC 3950.
=====
NGC 3950 is probably the faint elliptical galaxy 1.6 arcmin north of NGC 3949.
However, LdR's estimated distance from the brighter galaxy on the first night
he picked up the companion, and his accordant micrometric measurement three
years later in 1875, are clearly 1 arcmin too great. This is all the more
puzzling since he gives a table of measurements of six stars surrounding N3949
-- all of those measurements are very good (he notes one as possibly nebulous;
it is not).
Still, he could have seen the fainter galaxy, and it seems likely that he made
a simple error in its distance from the brighter.
=====
NGC 3952 = IC 2972, which see. The NGC identification is not in doubt.
=====
NGC 3953 has a faint companion seen once by Bindon Stoney in 1851 with LdR's
big telescope. See the story under "NGC 3953 companion" in the "notngc"
files.
=====
NGC 3954 is not NGC 3948, which see.
=====
NGC 3955. See IC 2970.
=====
NGC 3957 = IC 2965, which see.
=====
NGC 3964. See NGC 3927.
=====
NGC 3965 is probably the faint galaxy that I've noted in the table. It has a
star 4 arcmin north-preceding as noted by Francis Leavenworth. The star is
not as bright as his "9.5" -- V = 11.3, according to AC2000.2, but I would
expect him to overestimate the magnitude with a telescope as large as the
26-inch he was using. Nor is the galaxy unreasonably far off his position, 44
seconds of time preceding.
The mystery here is why neither I in SEGC, nor Jack Sulentic in RNGC, noted
the object. The declination is right, and I knew about the poor RA's in the
Leander McCormick lists, so why did I not pick it up? The magnitude more or
less matches Leavenworth's estimate (16.0), and the size is appropriate, too
(0.1 arcmin), as is his "R, bMN" note. Perhaps I just did not believe that
he could dig out a galaxy that faint.
While this should be checked visually, I'm fairly certain that the galaxy is
Leavenworth's object.
=====
NGC 3966 = NGC 3986. d'A's position (from a single observation) is one of the
few verifiably bad ones in his list. His description fits NGC 3986 perfectly,
and he notes the unresolved 12th magnitude double just southwest exactly in
its place relative to the galaxy. Finally, he comments, "Found while looking
for [N3986]; this is either a nova, or my RA is inexplicably erroneous." His
RA is 1m 30s off, and his declination is 10 arcmin off, too.
The galaxy chosen by Max Wolf as N3966 is actually IC 2981 (which see as it
has problems of its own). Wolf's note about N3966 in his 8th list was copied
into the IC2 notes by Dreyer, apparently during its final stages of
preparation since Dreyer did not include any of the 8th list objects in the
IC itself.
=====
NGC 3971 = NGC 3984, which see.
=====
NGC 3972. See NGC 3594.
=====
NGC 3975 may possibly also be IC 3166, which see.
=====
NGC 3977 = NGC 3980, which see.
=====
NGC 3978 may possibly also be IC 3180. See IC 3166 for the story.
=====
NGC 3979 = IC 2976. Here is a galaxy discovered twice by Lewis Swift, once
toward the beginning of his systematic sweeping for new nebulae (April 1886),
and once toward the end (May 1897). His first position is not too bad, being
only 8 seconds of time and 1.2 arcmin off the galaxy.
But he was not the first to see it; that was Edward Holden in April of 1881.
Holden found it first on the 23rd, but only estimated the RA then. On the
27th, he measured it at 42 seconds of time preceding the star BD -1d 2593.
And that position is close to the modern one. But for the NGC entry, Dreyer
chose to use an average, at least in RA, of Holden's and Swift's; he adopted
Holden's declination (about 1.5 arcmin north of the galaxy).
For the IC, of course, Dreyer had only Swift's second position, 1.5 minutes
off -- no wonder he thought Swift had found a new nebula! But there is
nothing in Swift's position. The identification is ensured by Swift's comment
about the "vF * near nf". This is the same star that Holden called "A star
11.5 n and f 30 [arcsec]."
=====
NGC 3980 = NGC 3977. Swift's position is only an arcminute following N3977,
there is nothing there, and the double star he notes is 3 arcmin following the
galaxy. The identity is sure.
=====
NGC 3981. There is a fairly wide range in positions from the various sources;
they pick out bright spots on the short bar which is oriented ssw-nne. I've
finally chosen the UCAC position as representative of the bar, but it may be
that there is a real nucleus hiding in the overexposed part that we can't see
easily.
=====
NGC 3984 is almost certainly the same object as NGC 3971. John Herschel
found N3984 during his Sweep 342 (10 April 1831), and described it as "eF, R,
bM, 25 arcsec." He adds an interesting note (aluded to in the IC2 Notes by
Dreyer): "Supposed at the time to be II.724 [NGC 3971], but on reducing the
obs, it differs 1 min in RA and 1 deg in PD, BOTH which can hardly be
mistakes" (Sir John's emphasis).
Yet the only reasonable solution is to say that both ARE mistakes. JH found
N3971 in Sweep 67 (2 April 1827), describing it "pB, R, bM. An exact obs."
The difference in estimated brightness is significant, but many of JH's
multiply-observed objects have the same wide range of description. Otherwise,
however, the descriptions for these two objects are the same. Also, the
position that he gives for N3971 is (within his usual statistical errors) 1
degree north, and 1 minute preceding N3984, just as he noted. Since each
nebula was noted in only one sweep, and since there are only very faint stars
in the vicinity of his position for N3984, I am going to adopt the identity.
=====
NGC 3986 = NGC 3966, which see.
=====
NGC 3990. See NGC 3594.
=====
NGC 3993 is not H III 324. WH's object is, instead, NGC 3997, which see.
=====
NGC 3996 is not NGC 4019, which see.
=====
NGC 3997 is the second brightest galaxy in a group of three found by WH in
1785. JH found it again 40 years later during his northern sweeps from
Slough, and LdR and his observers noted over a dozen companions in the area.
All these are in NGC, and Dreyer has the numbers pretty well sorted out
(though NGC 4009, which see, is a star; and NGC 4007, which also see -- due to
a 2 deg error in GC or in CH's reduction -- is identical to NGC 4005 also seen
by Otto Struve at St. Petersberg).
However, Dreyer, in his 1912 Scientific Papers of WH, has put the number
H III 324 on NGC 3993, presumably because it is the closest galaxy northeast
of H III 323 (= N3987). WH says only, "Suspected another nf, eF, 5 or 6
arcmin dist, pretty sure." Though his estimated distance falls directly
between N3993 and N3997, the latter galaxy is brighter, larger, and (in the
central regions at least) has a higher surface brightness. So, I'm pretty
sure that it is the one seen by WH. As I noted above, it was also seen by JH
-- it is, in fact, the only one of the group seen by him. He rather confused
the issue a bit by listing it as "III 323" in his 1833 catalogue.
=====
NGC 3998. See NGC 3594.
=====
NGC 4004 = NGC 4004A. The secondary designation comes from Holmberg's 1937
monograph and catalogue of multiple galaxies. He always called the brightest
galaxy of a multiplet "a", the second "b", and so on. In this case, "NGC
4004B" is IC 2982 (which see).
=====
NGC 4005 = NGC 4007, which see.
=====
NGC 4006 is not IC 2983, which see.
=====
NGC 4007 = NGC 4005. First found by WH in 1785, this object was recovered by
LdR and his observers, and by Otto Struve. Dreyer caught the identity when he
revisited the area during preparation of WH's Scientific Papers. In GC, JH
has the galaxy two degrees too far south, either because of a transcription
error by him or a reduction error by CH. See NGC 3997 for more on this group.
=====
NGC 4008. See NGC 3927.
=====
NGC 4009 is a star identified exactly by LdR's micrometric measurements
referred to a brighter star. It is often taken as the fainter galaxy 3.5
arcmin further northeast, but the measurements leave no doubt as to its
correct identity.
=====
NGC 4010. Found by JH, this large, almost exactly edge-on late-type galaxy is
rather similar to NGC 55 in having an eccentric bulge. In this case, the
bulge is offset to the northeast from the center of the outer isophotes. I've
chosen the SDSS position for most of the image as representative of the center
of the bulge, even though the galaxy is cut off at the southwestern end by the
edge of a scan. The position is obviously less certain than most.
=====
NGC 4013 is another edgewise galaxy, this one a somewhat earlier spiral than
NGC 4010 (which see). Finding the position for this one is somewhat
complicated by the star superposed almost exactly on the dust lane just
northeast of the center of the galaxy.
For this galaxy, the SDSS position is a bit south of the center of the galaxy,
so I've taken instead the mean of six 2MASS point sources clustered around the
approximate center of the bulge. Again, the position is more uncertain than
usual.
=====
NGC 4014 = NGC 4028, which see.
=====
NGC 4015. This is a double galaxy in the NGC 4005 group. Steve Gottlieb
notes that LdR picked up both objects on at least one night, though simply
called the northern object "... a tail n[orth] of Nucl[eus] ..." The NGC does
not comment on the "tail", nor does it note the object as double.
Not too long ago, I wrote here, "Nevertheless, I've included positions for
both objects in the position table with the NGC number." I've changed my mind
and have listed the northern object as a companion galaxy because it is clear
that the primary object that the visual observers picked up is the much
brighter southern one.
I went on to say, "Another place for the northern object might well be the
'notngc' files, but I've left it with its southern companion in the main NGC
position table." This comment needs no change or qualification at the moment.
=====
NGC 4019 = IC 755. Though JH's position is 2 min 16 sec and 6 arcmin off the
true position of IC 755, the IC object is the only galaxy in the area to have
a 9th magnitude star 5 arcmin southeast, matching JH's note. Other
possibilities include NGC 3996 (but seen in the same sweep as N4019), NGC
4037 (this has an 8th magnitude star following by 6-7 arcmin, but the star is
a bit north, not south), and CGCG 069-010 (but that has a pretty low surface
brightness and no bright star near).
There is nothing at JH's position, so I'm pretty sure that IC 755 is the
correct object. Malcolm notes, however, that there is a 9th magnitude star
southeast of JH's (empty) position. This throws a little doubt on the IC 755
identity, but requires that JH's object be a comet. This is a possibility,
but I think that the equality with IC 755 is more likely.
-----
Using JPL's "Small Body Identifier", I found that Comet 55/P Tempel-Tuttle was
about five degrees north of JH's position on the date of his observation of
NGC 4019. However, its predicted nuclear magnitude was 23.5. That, and the
position offset effectively rules it out as JH's object.
Checking the sweep (419 on 23 April 1832), I see that the RA is not only
marked with a colon, but that JH thought he was observing H III 3 = NGC 4028.
The position measurement is one of those that JH referred to a previous
measure, in this case a star with a clock, beat, and wire listed (11 51 45,
-19, leaving the field), but no NPD index. NGC 4019 has "-19" for the clock,
"-38" for the beat, "X" (leaving the field) for the wire, and "2 41 50" for
the NPD index. The nearest star in the sweep is [beta] Leonis at "11 40 35",
"-15", "1", and "2 19 36". Re-reducing JH's observation yeilds a position
with the RA two minutes larger than JH's published value. This brings JH's
object to within 20 seconds of time of the position of IC 755, so makes it
even more likely that the IC object is also JH's.
=====
NGC 4028 = NGC 4014, in spite of what JH had to say in a note in GC (repeated
by Dreyer in the NGC Notes). This is one of WH's early discoveries (30 Dec
1783). As with other objects found during the fall and winter of 1783-1784,
the position is not very good. However, WH's full record can be found in the
Herschel Archives (CH's fair copy) and was also published by Dreyer in the
1912 Scientific Papers. There, we find the note, "... It forms an isosceles
triangle with two small stars {Dreyer's note:} [by a diagram, these are about
6 arcmin sp.]. ..." The stars precede N4014 by the correct amount, so I am
pretty sure that it is WH's nebula.
This requires WH to have made two 2 min errors in his RA offsets from two
different stars on two different nights. While it is highly unlikely that he
would make two such errors leading to much the same position -- this is what
prompted JH's comment -- this is apparently exactly what happened. The
configuration on the sky is too outstanding to be mistaken.
=====
NGC 4032 is probably not NGC 4042, which see. Also see NGC 4055.
=====
NGC 4037. See NGC 4019.
=====
NGC 4042 is Marth 227, found the same night in March 1865 as N4056 (which see)
and N4060. If the offsets (about 10 seconds of time, and 1 arcmin) suggested
for those other two galaxies are even roughly correct, then N4042 can be
tentatively identified with a galaxy in GSC at 12 00 13.2 +20 26 31. The
declination offset would be the same as for the other objects, but the RA
offset would be considerably larger at 26 seconds.
Still, there are no other galaxies even remotely close to Marth's position
that would match his description. Another possibility is that N4042 is a star
somewhere in the area. RC1 raises the possiblility that it is identical to
NGC 4032, but that would lead to an error of over 2 minutes of time and 5
arcmin, making it unique amoung Marth's objects of that night.
In the end, I'm not sure what Marth really saw, but the galaxy 26 seconds off
his position seems the best choice.
=====
NGC 4045 (is also NGC 4046, which see), discovered by WH, was also seen by
David Todd during his search for "the trans-Neptunian planet" in 1877. It is
Todd's number (13b). See NGC 3604 above, as well as CGCG 013-049 (in the
"notngc" files) for more.
=====
NGC 4046 = NGC 4045. D'Arrest himself first suggested this identity, and
Dreyer repeated the suggestion in an NGC note. Unfortunately, the Mt. Wilson
observers (probably Hubble) took another, fainter galaxy on to the east (CGCG
013-049). This appeared as a "correction" to the NGC position in Table 3 of
Dorothy Carlson's 1940 ApJ paper.
However, reading d'A's full description makes it clear that he did in fact see
NGC 4045 (a joint translation from his Latin by James Bryan and me): "Makes a
triangle with two stars 13 and 16, southward and following the nebula 6.6
seconds." While the Mt. Wilson object does make a triangle with two stars,
they are nearly of equal brightness, and they are north and west of the
galaxy, not east and south.
The stars near NGC 4045 are close to where d'A says they are -- though it is
just possible that his southern star is actually CGCG 013-045 (sometimes
called "NGC 4045A"). This fainter galaxy has a faint star just southwest that
d'A might have seen. Eyepiece work is called for here.
D'A's eastern star, the brighter of the two, is closer to 5.5 seconds east
rather than his 6.6 seconds. Is this perhaps a typographical error of some
sort? It seems more likely to me to be simply a rough observation.
So, the bottom line is that d'A certainly made a 15 arcminute error in his
declination. The identity is therefore sure.
=====
NGC 4052. There is nothing at JH's place, but 1 minute of time west is a
cluster, about 9 arcmin by 9 arcmin, that fits his description ("Cluster VII
class; loose and scattered, but pretty rich."). I have no doubt that this is
his intended object.
This is one of the very few that Brian missed; his position (12 00 00,
-63 13.6; J2000) is for a random star field two minutes of time preceding the
cluster. His estimated diameter, however, 7.5 arcmin is roughly correct. Is
the RA perhaps a typo?
=====
NGC 4055 = NGC 4061, NGC 4057 = NGC 4065, and NGC 4059 = NGC 4070. John
Herschel found these three nebulae during his Sweep 423 on 29 April 1832.
They have not been positively identified in any published catalogue since,
though Reinmuth and PGC have made suggestions. Here is the story.
Steve Gottlieb started the case by noting that Reinmuth's identifications were
unlikely. Bob Erdmann followed up with the suggestion that these might be
identical to some of the galaxies in the NGC 4065 group 0.8 deg south. Then,
Brent Archinal suggested a check of the other objects seen by Herschel in
the same sweep. Here is what is in his 1833 catalog credited to Sweep 423
(there may be one or two others lurking in the list, but I haven't found them
in two reasonably careful searches. My comments are in square brackets):
NGC h RA (1830) NPD Desc
3937 1003 11 43 56 68 25.1 vF, S, R
4032 1049 11 51 49 68 58.2 pB, R, gbM, 40" [N.B. Seen in 5 other
sweeps where the brightness ranges
from "B" to "eF"; the positions agree]
4055 1062 11 55 00: 68+- pB
4057 1063 11 55 04: 68+- pB
4059 1064 11 55 08: 68+- pB. On merid[ian] with two more [I presume
the other two are N4055 and N4057]
4066 1068 11 55 26 68 41.9 No description [Seen in 3 other sweeps;
the positions agree. Those descriptions
are "Not vF. Another seen", "pB", and
"The third of 5"]
4095 1079 11 57 13 68 28.1 eF [seen in one other sweep; position agrees,
but no description]
4098 1082 11 57 22 68 25.5 No description [two other sweeps: positions
agree; "vF, R, bM" and "No description"]
Looking at this table, I was struck by a couple of things. First, the north
polar distances of the three questionable objects have been assigned the same
number of degrees as the other five objects. This suggests to me that the
minutes of NPD should be similar to the others -- say 68 30 to 68 50 -- since
Herschel's sweeps were pretty limited in declination. This would make the
NPD's roughly equivalent to the other bright objects in the core of the NGC
4065 group where the NPD's range from 68 38 to 68 53. Second, the
descriptions suggest that the objects are not faint, and that they are aligned
pretty closely along the same meridian of RA.
The NGC 4065 group has four bright objects: N4061, N4065, N4066, and N4070.
Since Sir John saw N4066 during the sweep in question, this leaves N4061,
N4065, and N4070 as the possible candidates. Interestingly, his more exact
positions for N4055, 57, and 59 given in GC (from "a most careful
consideration of all the observations and records in the sweeping books" [note
in GC], and copied into NGC by Dreyer) are roughly coincident with these three
galaxies if a systematic offset of about -0.88 degrees in Dec and +20 seconds
in RA is applied.
Putting all this together, Occam's Razor (the simplest hypothesis that fits
the facts) suggests that
NGC 4055 = NGC 4061
NGC 4057 = NGC 4065
NGC 4059 = NGC 4070
I'm not sure about this, of course. But this is certainly a reasonable
solution to the problem.
There is more discussion of the identities in the group under NGC 4056 and NGC
4069.
=====
NGC 4056 and NGC 4060. Albert Marth found these two objects in the area of
the N4065 group during his Malta observations of March 1865 with William
Lassell's 48-inch reflector (these are m229 = N4056 and m230 = N4060; their
data are transcribed correctly into NGC). These do not have good positions
(neither was "verified" by Marth), and the descriptions are vague enough to
make identifications unsure.
One possibility is N4060 = RNGC 4056; Marth's position is close to that
galaxy. However, that leaves the question of N4056. Marth's position is near
a very faint galaxy that I doubt could be dug out visually even with the
48-inch -- is N4056 perhaps the star preceding Marth's position by about two
arcmin? Another possibility is that N4060 = RNGC 4069 and N4056 = RNGC 4056;
this would require a systematic offset of about 10 sec in RA and 1 min in dec
for Marth's positions. (Another object, m227 = N4042, which see, found by him
the same night, could then be identified with a faint galaxy in the GSC with
the same declination offset, but would require an RA offset of 26 seconds.)
Even with the offsets, however, the positions would not be good matches for
the positions of the galaxies in the group.
Finally, there is the RNGC "brute force" solution: ignore the positions and
simply assign the numbers to the two relatively bright galaxies in the area
that do not have other NGC numbers. If we accept this idea, N4060 is at least
north-following N4056, though the difference in RA is about one-third of the
difference given by Marth. Still, this could be the correct interpretation,
so we'll go with it for the time being.
See NGC 4069 for more on this confused field.
=====
NGC 4057 = NGC 4065. See NGC 4055.
=====
NGC 4059 = NGC 4070. See NGC 4055.
=====
NGC 4060. See NGC 4042, NGC 4056, and NGC 4069.
=====
NGC 4061. See NGC 4055 and NGC 4069.
=====
NGC 4063, discovered by Stephan, was also seen by David Todd during his search
for "the trans-Neptunian planet" in 1877. It is Todd's number (12d). See NGC
3604 for more.
=====
NGC 4065 = NGC 4057. See NGC 4055 and NGC 4069.
=====
NGC 4066. See NGC 4055 and NGC 4069.
=====
NGC 4067. See NGC 4368.
=====
NGC 4068 = IC 757, which see. Bigourdan misidentified a star as NGC 4068 on
two nights, apparently misled by the NGC description "stellar." This led him
to rediscover the galaxy and claim it as a "nova."
WH's own description "A pS star involved in nebulosity of no great extent; the
star does not seem to belong to it" matches the galaxy and its brightest
superposed star very well. I suspect that JH condensed the description while
preparing the GC.
See IC 757 for more.
=====
NGC 4069. This is one of the galaxies found by John Herschel during the
problematic Sweep 423 of 29 April 1832 (see NGC 4055 for a list of the nebulae
found during the sweep). Unfortunately, Herschel saw it only during that one
sweep, so its position is not well-determined. Also, it is in the midst of a
group of nebulae found by William Herschel, and later reobserved by Heinrich
d'Arrest. Making reasonable assumptions about the six objects found by Sir
William (he measured positions only for the northern three of those he saw,
saying only that the other three were 10-12 arcmin south) leads to the
conclusion that d'Arrest got the same six. NGC 4069 (= h1070) is not among
them, in spite of the identity with H III 392 given in NGC. The three
measured by Herschel are N4066, N4070, and N4074; and his other three to the
south must be N4061, N4065, and N4076. These are the six brightest objects in
the group.
There are four other NGC objects scattered through the group. Unfortunately,
only one can be pinned down with any certainty. That one is NGC 4072,
discovered by Ralph Copeland with Lord Rosse's Leviathan. His description
(dated 3 April 1872) also makes it clear that he saw the fainter galaxy two
minutes north-following N4076. The confusion in the positions, though, led
Dreyer to not assign an NGC number to this galaxy.
In any case, N4069 is one of the remaining three (the other two are N4056 and
N4060, found by Marth; see the discussion of these). RNGC makes N4069 the
faint galaxy just north-preceding a star (both are in GSC), but the nearby
RNGC 4060 is considerably brighter. Herschel's description, however, "vF, R,
4th of 5; has another on same meridian, north" doesn't support the identity
with RNGC 4060. There is the possibility, however, that the star just
south-following RNGC 4069 was "blended" with the galaxy so that the two
objects together would appear as a single brighter nebula. This would save
the description of "another on the same meridian, north," and would be
relatively close to Sir John's position. Lacking any better hypothesis at the
moment, we'll adopt the RNGC identification.
=====
NGC 4070 = NGC 4059. See NGC 4055 and NGC 4069.
=====
NGC 4072. See NGC 4069.
=====
NGC 4073, discovered by WH, was also seen by David Todd during his search for
"the trans-Neptunian planet" in 1877. It is Todd's number (12a). See NGC
3604 for more.
=====
NGC 4074. See NGC 4069.
=====
NGC 4075, creditted in the NGC to JH, was also seen by David Todd during his
search for "the trans-Neptunian planet" in 1877. It is Todd's number (11).
See NGC 3604 for more.
=====
NGC 4076. See NGC 4069.
=====
NGC 4077 is also NGC 4140. See NGC 4139 for more.
=====
NGC 4078 = NGC 4107, which see.
=====
NGC 4082. See NGC 4107.
=====
NGC 4083. See NGC 4107.
=====
NGC 4086. See NGC 4090 and IC 759.
=====
NGC 4090 is not IC 2997 (which see). Both were seen on the same night by
Bigourdan, though he included only his observations for I2997 in his big
table. The observations for N4090 are in his Appendix VIII of complementary
observations.
Another curiosity with this object is its NGC right ascension from d'Arrest's
observation. D'A found both this and NGC 4086 on the same night, and mentions
this object in his note for N4086. However, while his RA for N4086 is about
right, he puts this object about 10 seconds of time following its true
position 1.5 seconds preceding N4086. Since both are visible in the same
eyepiece field, I suspect that this is a simple digit error somewhere in d'A's
reduction.
=====
NGC 4092, not NGC 4093, is almost certainly H III 382. WH saw three galaxies
in this group, most plausibly the brightest three. So, Dreyer's supposition
that the first of the three is N4093 is probably wrong, just as JH's idea that
III 382 is NGC 4095 (note, too, that JH has a misprint in his list making his
father's object "II 382"). N4092 is a magnitude brighter and considerably
larger than N4093, so is probably WH's object. His other two are NGC 4095 and
NGC 4098 = NGC 4099, both of which see.
=====
NGC 4093 is probably not H III 382. See NGC 4092 for more.
=====
NGC 4095. The RC3 position is from MCG. GSC has 12 03 21.05 +20 51 03.6
(1950) for this galaxy. The relatively small difference in position normally
wouldn't matter to the identification, but the galaxy is in a fairly compact
group with five other NGC objects. Four of the six galaxies are in RC3, and
as far as I can tell with a quick check of MCG, UGC, and CGCG, the data for
each have been assigned correctly.
This is also the second of the three objects that WH found (III 383). The
first is NGC 4092 (which see), and the third is NGC 4098 = NGC 4099 (also
which see). Dreyer reassigned WH's numbers in the 1912 Scientific Papers,
getting this one and III 384 correct.
Also see NGC 4055.
=====
NGC 4098 = NGC 4099, which see. Also see NGC 4055.
=====
NGC 4099 = NGC 4098. WH found three nebulae in this group. It's reasonable
to suppose that he saw the three brightest (two of these were seen by JH, and
the others were found by d'A); these are NGC 4092, 4095, and 4098. As Dreyer
realized in 1912, this would make the number 4099 = GC 2714 irrelevant as it
was added (by JH) explicitly for H III 384, the third of his father's three.
On the DSS image, this looks like an interacting double galaxy (it may be a
triple -- there is a broad plume extending on to the southeast that may be a
third component). The two are well merged, so the early observers would not
have seen them as separate objects. So that won't save the extra NGC number
(nor IC 2998, which see).
=====
NGC 4107 = NGC 4078 with a 2 minute error in d'A's RA. The object is
positively identified by the "star 10-11 30.2 seconds following, 1 arcmin
south." Just north of this star is a line of three faint galaxies, two
(N4082 and N4083) seen by Marth with William Lassel's 48-inch reflector, the
third found by Frost on a Harvard plate. All are faint enough that d'A could
not have seen them with his 11-inch refractor.
There is a curious footnote to this: Burnham claims to have seen the nebula
in 1891 with the Lick 36-inch, and also says that the star is north-preceding,
not south-following as d'A has it. Since I haven't yet seen Burnham's notes,
I can't say anything about this except to speculate that Burnham saw a
different object. We can also speculate that he would have noticed the RA
error had he picked up N4078.
-----
Since I wrote that previous paragraph, Wolfgang has kindly sent me a copy of
Burnham's note which appears in Publ. Lick Obs. 2, 163, 1894 (his discoveries
of IC 258 and IC 259, which see, are at the end of this paper). It reads in
full:
No. 4107
R.A. 11 59 35
Decl. +11 23
Not planetary, but it is brighter in the middle, and extended in the
direction of 115 deg. In Dreyer, it is described as having a star 10-11m
south following. There is nothing in that place, but there is a star of
that magnitude north preceding.
Wolfgang points out that there is a fainter star very near to the west of the
galaxy. Since Burnham does not mention a distance to his star, and since
d'A's star is a considerable distance away, it's possible that Burnham did not
notice d'A's star. It is also possible that he simply got his directions
confused.
Whatever happened, it's clear that Burnham got the right galaxy -- his
position angle is accurate for NGC 4107.
=====
NGC 4108. See NGC 4512.
=====
NGC 4113 = NGC 4122. JH has only one observation of N4113, calling it only
"eF." His position -- from a different sweep -- is exactly 1 degree north,
and 1 minute of time west of N4122, and his brief description is appropriate.
His position for NGC 4122 is correct.
=====
NGC 4115 is perhaps the 14th magnitude star near JH's position. There are no
nebulae nearby, or at digit errors from his nominal position, that he might
have picked up while sweeping. He also notes it as "A suspected nebula,
extremely faint" which the star would have been were it seen on a less than
perfect night.
-----
The sweep has exactly the same information, and the position is correctly
reduced, so the star seems the likely object that JH picked up.
=====
NGC 4119 = IC 3011 (which see) is also probably NGC 4124 as suggested by
Dreyer in WH's Scientific Papers. WH's final position is just 50 arcmin south
of N4124, and there are no other bright galaxies nearby that he might have
picked up.
It is worth noting, too, that this is one of his early discoveries (18 Jan
1784). Many other of his nebulae and clusters found during the winter of
1783-84 (his first season of sweeping) have relatively poor positions (see
e.g. NGC 4153 and NGC 6533). Dreyer notes that N4124 already has two certain
numbers in WH's lists, I 33 and II 60. The positions for these observations
are better, but are still enough different -- along with the differing
descriptions "B, L, ..." and "F, S" -- that WH listed them separately.
=====
NGC 4122 is also = NGC 4113, which see.
=====
NGC 4124 = IC 3011 is also probably = NGC 4119, both of which see.
=====
NGC 4129 = NGC 4130, which see.
=====
NGC 4130 = NGC 4129. D'A's declination error of 5 degrees for NGC 4130 is
comfirmed by his exact description of the galaxy and the star 21 seconds
preceding it. There is no problem with the Herschels' several observations of
NGC 4129.
=====
NGC 4139 = IC 2989. The RA's of this and its companion NGC 4140 are 5 minutes
of time too large. When corrected by this amount, the positions agree closely
with those for IC 2989 and NGC 4077, respectively. The descriptions clinch
the identities, and RC3 is correct.
This pair was also seen by David Todd during his search for "the trans-
Neptunian planet." It is his numbers (14a) and (14b), as well as (16a) and
(16b). See NGC 3604 for more about David Todd and his search.
=====
NGC 4140 = NGC 4077. See NGC 4139.
=====
NGC 4147. See NGC 4153.
=====
NGC 4149 = NGC 4154. The two NGC numbers are due to WH having swept this
galaxy up twice in succesive years, 1789 and 1790. JH has only one
observation of it with no description which he put on his father's 1789
observation. Dreyer noted that Bigourdan did not find NGC 4154 (the 1790
observation), but WH's position for this is actually closer to the galaxy than
his position for N4149 which Bigourdan did observe.
In any event, there is no doubt that the two numbers apply to the same galaxy.
Steve Gottlieb (who called my attention to this) and Wolfgang Steinicke were
apparently the first to notice the identity. Though I have the correct
position for each object, they are just far enough apart in my working table
(separated by many good positions for NGC 4151) that I did not see the
identity. Good catch, guys!
=====
NGC 4152. See IC 765.
=====
NGC 4153 is probably NGC 4147. This was found by WH on 15 Feb 1784, only two
months after he started observing with his first "20-feet" telescope. He put
the nebula 1m 30s preceding, 2d 11m south of 5 Comae. This gives 12 08.1 +18
38 (1950) for the nebula. Herschel described it as "B, pL, lE, bM, m[ilky]."
It has not been seen since at this position.
The closest reasonable object that might be the missing nebula is another
early discovery of WH's, NGC 4147 = H I 19, the bright globular northwest of
the Virgo Cluster. Herschel found this just a month after N4153 (14 March
1784), and placed it at 10m 30s preceding, 0d 46m north of 11 Comae. This
becomes 12 07.7, +18 50 (1950), in pretty good agreement with modern positions
for the cluster. WH's description is very much the same as that for N4153:
"vB, pL, gbM."
At the time WH found N4153, he was still improving his method of determining
positions. So, I suspect that the February observation, earlier on the
"learning curve," actually refers to NGC 4147.
I also recall a Sky and Telescope article on this mystery object. It appeared
many years ago, perhaps in the late 50s or early 60s. Someone whose S&T's are
not buried in the storeroom might want to dig it out. It is not a "Deep Sky
Wonders" article, since Walter Scott Houston's article -- at least as printed
in the book edited by Stephen James O'Meara -- that mentions N4153 calls it a
"true faint external galaxy ... about 13' south and about 8' east of NGC
4147." The declination would be close to WH's, but the RA is well off. And
there is nothing in this position, either.
=====
NGC 4154 = NGC 4149, which see.
=====
NGC 4160. Bigourdan has two accordant observations of this object on 27 May
1886 which place it 12.87 seconds east and 1 arcmin 24.8 arcsec north of "AG
Bonn 8386" = SAO 044068. However, there is nothing there. A quick glance
at the POSS1 shows another star about 35 seconds following and 40 arcsec north
with a faint double star north following. The DSS gives the 1950 position of
the double as 12 09 31.0, +44 00 49. Assuming that this is Bigourdan's
object, and that he misidentified his comparison star, I reduced his
observation. The resulting position is 12 09 41.0, +44 00 59. The 10 second
and 10 arcsec differences are striking, but are difficult to understand given
that Bigourdan read his micrometer in terms of position angle and distance and
later reduced them to RA and Dec offsets.
Since there is still nothing at Bigourdan's place (assuming the mistaken
identity for the comparison star), I'm tempted to assume some kind of error in
his observation leading to the digit errors. But so far, I've not been able
to find it.
=====
NGC 4163 = NGC 4167, which see.
=====
NGC 4164 and 4165. There is no doubt concerning the identifications of these
two galaxies, yet UGC missed the NGC number for N4164. This is probably just
an oversight. However, one comment: Tempel expresses some surprise that
d'Arrest should have missed N4164; Tempel seems to think that the two galaxies
are nearly equal in brightness. However, N4164 is a full magnitude fainter,
and much smaller than N4165. There is a 15th magnitude star about 30 arcsec
south-following that may have provided the illusion of a brighter nebula in
Tempel's relatively small 11-inch refractor. Still, I'm not at all surprised
that d'Arrest picked up N4165 alone.
N4165 itself is identical to IC 3035, which is from Schwassmann's list of
photographically discovered nebulae in the Virgo Cluster. There can be no
doubt about this as Schwassmann included other NGC objects, and his position
falls much closer to N4165 than to the tiny companion just north-preceding.
Nilson realized this, too, and corrected the mistaken entry in CGCG where
the north-preceding galaxy is called I3035. Since Schwassmann was working
on a plate taken with a telescope of 6-inches aperture, it's doubtful that
the fainter galaxy is on the plate at all (the plate, by the way, has been
lost. Wayne Johnson requested a print of it from Heidelberg along with the
other prints of the discovery plates for many of Wolf's IC objects, but
Schwassmann's plate could not be found).
=====
NGC 4165. See NGC 4164.
=====
NGC 4167 = NGC 4163. JH first suggested the identity of his h1118 with his
father's H III 399 in his 1833 catalogue -- it is clinched by the existence of
the bright double star (SAO 62887/8) 10 arcmin southwest of the galaxy; JH
mentions the double in his description. His position is exactly 20 arcmin
off; when that is taken into account, his position falls close to his father's
place for the galaxy.
=====
NGC 4169. See NGC 4170.
=====
NGC 4170 and 4171. Found by d'Arrest near the group of four galaxies NGC
4169, 4173, 4174, and 4175, these two objects are probably stars picked up on
a night of below-average seeing. D'A's entire observation (translated to
colloquial English by a Latin teacher, and relayed courtesy of Steven Dick and
Brent Archinal at USNO) reads in full: "In addition, I think I see two other
nebulae very close to this one [NGC 4169]; a clearer sky would help." His
note for the night (10 May 1864) reads: "Wind; not perfectly clear." The
approximate positions in the NGC apparently come from Dreyer. And that is the
extent of the original "data."
There are no other nebulae near the quartet found by the Herschels. Given
d'A's scanty observation, we can safely conclude that these two objects do not
exist as nebulae. As I said above, I suspect they are stars.
An interesting side note: Yann Pothier brought these objects back to my
attention. His mother, also fluent in Latin, commented -- based on the
sentence describing these nebulae -- that d'A's Latin was not very good. Here
is the complete sentence for those of you who would be able to read my PhD
diploma: "Praeterea visus sum mihi videre duas alias nebulas huic valde
vicinas, quae Astronomis, Coelo adjutis sereniore, relinquuntur."
=====
NGC 4171. See NGC 4170.
=====
NGC 4173. The position I've chosen applies to a very faint red knot, possibly
the nucleus, in the center of the eccentric bar. The approximate center of
the outer isophotes is close to 20 arcseconds northwest of this position; the
SDSS algorithm took this as the center of the entire galaxy, as did the
Hickson Atlas, and Jaffe and Gavazzi in their Coma Supercluster study of 1986.
It's possible that a position intermediate between these two may best
represent the galaxy. However, I have retained the position for what appears
to be the nucleus, as it is the brightest part of the bar in the DSS2 infrared
image.
The galaxy itself is probably a slightly distorted SB(s)dm pec seen nearly
edge-on. It is the largest galaxy in the compact group Hickson 61 with
NGC 4169, NGC 4174, and NGC 4175. See NGC 4170 for a mystery concerning two
other NGC objects in the area.
=====
NGC 4174. See NGC 4170.
=====
NGC 4175. See NGC 4170.
=====
NGC 4178 also carries the number IC 3042, which see.
=====
NGC 4179, discovered by WH, was also seen by David Todd during his search for
"the trans-Neptunian planet" in 1877. It is Todd's number (15). See NGC 3604
for more.
=====
NGC 4180 is perhaps also NGC 4182, which see.
=====
NGC 4182 may be NGC 4180, or it may simply be a star at Peters's position.
That position is 3 degrees south and 17 seconds following NGC 4180. Arguing
for the identity is his observation of NGC 4191. Both it and NGC 4180 are
about 13th magnitude, and close enough together on the sky that it is
difficult to understand how an observer could see one but miss the other.
On the other hand, Peters's position for NGC 4191 is only 4 seconds following
the true position -- his measured separation for the objects (assuming only a
3 deg error in declination) does not match their separation on the sky. And
the star at his quoted position is faint enough that it could have been
mistaken for a nebula.
In the end, we would need to re-examine Peters's charts to find the objects
that he thought were nebulae. Until then, I slightly favor the NGC 4182 = NGC
4180 idea, though not by much.
=====
NGC 4184 is a group of faint stars just where JH says it is. The object was
rediscovered over a century later by Ruprecht (it is his number 102), but the
NGC number was not attached. Thus, the "non-existent" status in RNGC.
It has two concentrations of stars. While JH's position more closely
coincides with the eastern, it seems likely that the somewhat richer western
one is also a part of the cluster. But there is considerable patchy Galactic
obscuration in the area, so only a full investigation of the field will serve
to clearly delineate the real cluster here. I've estimated positions for
both concentrations.
There is a richer cluster of much fainter stars nearby at 12 13 03.6,
-62 42 24 (J2000; HCsv, DSS2IR). This is Alessi J12130-6242, discussed by
Archinal and Hynes in their 2003 book, "Star Clusters". This is much too
faint to have been seen by JH, so is only coincidentally near NGC 4184.
=====
NGC 4185 may also be NGC 4209 (which see) -- but is probably not.
=====
NGC 4186. Tempel mentions this object in two of his papers (AN 2212 and AN
2439). In the earlier paper, the offset from M 98 (= N4192 = GC2786) is given
as -10s and -10', leading to a position listed as 12 06 15 +15 32 (1855) [12
06 30 +15 30 (1860)] which is 10s off the NGC place (12 06 20 +15 31).
However, the later paper lists the offset as +20s, -9.5m which gives 12 07 00
+15 31 (1860). This position agrees with that from Zwicky for an Sa galaxy
with mp = 14.9; this was also earlier mentioned by Carlson (1940). The
mistake seems to have been Dreyer's: he applied the right ascension offset
(from Tempel's later paper) with the wrong sign.
Carlson and RC2 are correct; RNGC, UGC, and VCC are incorrect.
=====
NGC 4189 = IC 3050, which see.
=====
NGC 4191. See NGC 4182.
=====
NGC 4192 = M 98. See NGC 4186, NGC 4548, and NGC 4579.
=====
NGC 4193 = IC 3051. See IC 3050.
=====
NGC 4196. See NGC 4209.
=====
NGC 4198 = IC 778, which see.
=====
NGC 4199. Dreyer has a note in his 1912 collection of WH's papers that caught
my curiosity: "Also observed in Sw. 953, Mar. 19, 1790, 76 Ursae p. 27m 59s,
s. 2d 50', or I.253, f. 13m 47s, s. 1d 59'. This agrees well with the place
of Bigourdan, which is = N.G.C. -37s +4'." This seems to suggest that WH
might have seen two nebulae here, not just one.
However, reducing his observations, I find just a single galaxy with
considerable scatter in WH's reduced positions. For 2000, those positions and
the reference objects are:
12 14 31 +59 57.9 69 Ursae Majoris
12 14 26 +59 57.5 71 Ursae Majoris
12 14 44 +59 52.0 76 Ursae Majoris
12 14 44 +59 54.8 I.253 = NGC 4036
Only the last is fairly close to the faint double galaxy that WH must have
seen. It has a superposed star involved, too, that must have enhanced its
visibility a bit. I've taken all three objects as WH's object, though the
southwestern galaxy is the brighter of the pair. While I suggested earlier
that the star might be brighter than either galaxy, it is actually the
second-brightest of the three objects, at least in V. The southwestern galaxy
is therefore almost certainly the object that WH saw.
Bigourdan found the correct object, but made two errors in transcribing his
observations for publication. First, he makes his declination offset negative
instead of positive; and second, he has a -1 minute error in the RA offset
between BD +60 1384 and his actual comparison star, a 12th magnitude star
fortunately picked up in the Astrographic Catalogue zone; this means that we
have a good position for it at an epoch close to Bigourdan's observation
date.
Once these problems are corrected, Bigourdan's position falls within a few
arcsec of the star superposed on the galaxy pair.
The galaxies, by the way, are probably members of the nearby galaxy cluster
Abell 1507. The redshift of the northeastern galaxy is z = 0.0612, while that
of the southwestern is z = 0.0605; the redshift of the cluster is z = 0.0604.
=====
NGC 4202. David Todd's published article has a sketch of the field of this
galaxy that unambiguously identifies it with UGC 7337. It is his number (18).
The RC3 is correct; RNGC is not.
See NGC 3604 for more about Todd's search for "the trans-Neptunian planet."
=====
NGC 4206 = IC 3064. See IC 3050.
=====
NGC 4208 = NGC 4212. This one requires a coincidence of errors by both WH
and JH. Though both nebulae were seen by WH in a single sweep, Dreyer has
shown (in the Scientific Papers) that the objects could be identical if WH
reset his telescope after fixing on a star.
In his NGC note, Dreyer suggests that JH made a simple digit error in the RA
of h1142 = N4208 -- it was seen only once in a different sweep than h1144 =
N4212 (which has four accordant observations). This placed h1142 close enough
to H II 107 that JH assumed the identity.
Though remarkable, such a coincidence is almost sure to happen at least once
in the crowded area of the Supergalactic equator. Since there are plausible
explanations for both errors, I'm willing to accept Dreyer's identity of the
"two" nebulae.
=====
NGC 4209 may be NGC 4185. Or it may be a star about 2 arcmin south-southwest
of WH's position.
The problem with equating N4209 and N4185 (which is about 2 minutes west of
N4209) is that WH found them both during the same sweep (396 on 11 April
1785). Dreyer's note in the Scientific Papers is a bit misleading as it
suggests that the position of NGC 4209 is somehow dependent on that of NGC
4196 (which precedes NGC 4209 by 1min 18sec in the sweep) -- it is not. NGC
4196 indeed has its transit recorded to a full minute only, but NGC 4209 has
both minutes and seconds recorded. Dreyer was right, however, that JH, d'A,
and Bigourdan all did not find the object.
I also do not see anything in the sweep that would suggest that either NGC
4185 or NGC 4209 was observed out of order, or that they could be the same
galaxy. However, Dreyer has shown us (see e.g. NGC 4208) that WH, at least
once, probably unknowingly observed the same galaxy twice in the same sweep.
But that does not seem to have happened here.
Wolfgang Steinicke has chosen the star noted above as being N4209. This is
certainly possible as there is nothing else within 5 arcmin of WH's position
that he could have seen. However, WH's description "F, pS" does not give us
very much to go on. The size "pS", by the way, would make the object larger
than NGC 4196 which is described as "F, S". If it were the star, I would have
expected WH to say "vS" or "eS". Perhaps there was a momentary burst of very
bad seeing ...
At the moment, I favor taking Wolfgang's star, but am not yet convinced that
this is WH's object.
=====
NGC 4210. See NGC 4512.
=====
NGC 4212 = NGC 4208, which see.
=====
NGC 4214 = NGC 4228, which see.
=====
NGC 4215. There is no question about the identification of this galaxy.
However, Schwassmann's photographic position is exactly six arcminutes too far
south. This must be a simple typo as his printed differences between the NGC
position and that from Monnichmeyer from micrometric measurements at Bonn are
very small. Fortunately, though NGC 4215 is the very first object in
Schwassmann's list, its position is not representative of any systematic
problem in the remainder of the list. There are a few more accidental
mistakes, and some missed NGC identifications, but in general, the positions
are quite clean, and reasonably accurate.
=====
NGC 4216 has a faint companion to the north see first by Samuel Hunter with
LdR's giant Parsonstown reflector in 1860. See the short story under CGCG
069-113 in the "notngc" files.
=====
NGC 4217 is a large, almost exactly edge-on spiral. Its nucleus is completely
obscured by the thick dark lane. Given this, one of the 2MASS positions is
the obvious one to use, so I've taken the position from the Extended Source
Catalog -- it is the closest to the mean of the 17 positions I've collected by
March 2015. This is perhaps a coincidence, but the 2MASS XSC position is
nevertheless representative of how we see the galaxy optically and in the
near-infrared. I have not yet seen a radio position of equivalent accuracy.
=====
NGC 4221. See NGC 4512.
=====
NGC 4222 is not IC 3087, which see.
It is, however, a late-type spiral seen virtually edge-on, just as NGC 4217
is. Thus, its position is difficult to determine. The one I have finally
adopted is from the 2MASS Extended Source Catalog, and is centered on an
IR-bright knot just northeast of the apparent center of the nearly
non-existent bulge.
=====
NGC 4223 = IC 3102 and NGC 4241 = IC 3115. There are several curious things
going on here, the least of which are the equalities with the IC numbers!
Here are two galaxies, both seen by both Herschels, yet Dreyer has all but
insisted on dropping the NGC number 4223. I'm not really in favor of this at
the end of the story -- but we need the story first.
WH found the brightest (H II 137) of the two galaxies on 13 April 1784,
placing it "f 11 Virginis 7 min 18 sec, 0 deg 55 arcmin north." As Dreyer
noted, these offsets reduce to 12 15 13, +06 58.6 (B1950). WH's second
observation, from 28 Dec 1784, reduces to 12 14 49, +07 00.1, which is close
to the actual position of the brighter galaxy of the pair. That these
observations refer to the same nebula is obvious from WH's note about III 480
(seen only on the second night): "L, vF, would not have been seen if it had
not been for the preceding [II 137]." WH's position for the fainter object
is also very close to the true position.
JH also has two observations of the brighter galaxy -- his positions are
accordant with each other, and with his father's second position. However --
and here is where the confusion sets in -- he calls this brighter galaxy III
480. On his second sweep, he also has an observation of an object which he
calls II 137, but of it he says, "pB, R, RA estimated from III 480, which it
precedes on the same parallel." All that is true. But the position he gives
for this brighter object is a minute of time earlier than it should be --
there is no nebula there. Somehow, JH has got his absolute positions about
a minute of time west of the true positions.
JH, of course, used his own positions in GC, and Dreyer copied them into the
NGC noting that d'A never saw the preceding of the pair. However, while
working on the Scientific Papers, Dreyer looked again at the problem, this
time finding that H III 480 is = IC 3115, and that II 137 = NGC 4241
(apparently not noticing that N4241 would also be = IC 3102 in this scenario).
This leaves the number 4223 without a galaxy -- yet WH's observations are very
clear that his II 137 applies to the brighter, western object. This would be
N4223. This makes the fainter eastern object III 480 = N4241. All this is in
accordance with the numbers in the GC and the NGC itself. The only incorrect
data are the RA's which are about a minute of time (N4223) and 30 seconds
(N4241) too far west.
This leads me to suggest that the simplest solution is to adopt WH's
positions, descriptions, and numbers. The only problem is that the number
N4241 has been applied to the brighter galaxy for so long that confusion will
undoubtedly result. My feeling is, "So be it."
The IC numbers are unambiguous as Schwassmann's positions are very good. The
question of why he did not assign the NGC numbers is pretty clear from the
mess above. I would have thought, however, that either he or Dreyer would
have caught the equality of the positions for I3102 and N4241 (as published in
NGC); apparently, neither checked carefully enough, perhaps thrown off by the
RA problems.
An addendum: The mess with these two NGC numbers may not be the reason that
Schwassmann did not assign them in his list -- he may simply have missed them.
There are at least two other NGC/IC equalities in his list: NGC 4235 = IC
3098, and NGC 4246 = IC 3113. There are no big problems with the NGC
positions in these cases, yet he has not put the NGC numbers into his list.
So, the galaxies also went into the IC. See those IC numbers for a bit more
discussion.
=====
NGC 4228 = NGC 4214. The equality was first implied by d'A, and later taken
up at Lick, by Reinmuth, Carlson, and in RC1 and RNGC. The problem is simply
an error of 1 minute of time in JH's position for the galaxy the first time he
saw it (Sweep 72). He got it right the second time (Sweep 331).
=====
NGC 4230 was misidentified in ESO and by Brian Skiff (and perhaps by others as
well). Their positions point at an apparently real cluster roughly 12 arcmin
northeast of JH's position. There is a bright star, HD 106826, superposed on
the cluster just northwest of the core, a star with V = 8.5 that JH surely
would not have called "12th magnitude" as he did the star near the center of
his object. Brian took the position of the HD star as that of the cluster,
while Andris Lauberts measure the position of the core itself. My own
estimated position may be also for just the core.
JH's object is a much more scattered grouping and may not be a real cluster.
It is centered about an arcminute northeast of the 12th magnitude star which
JH measured and took as the position of his cluster. The V magnitude of the
star is 11.6, close to JH's estimate. I make his cluster 7 arcmin by 5 arcmin
in diameter on the DSS cutout, in good agreement with JH's estimate of
6 arcmin.
=====
NGC 4235 = IC 3098, which see. Also see NGC 4223 = IC 3102.
=====
NGC 4236. While there is no question about the identification of this large,
low surface brightness galaxy, its accurate position is not easily determined.
There is no nucleus visible at any wavelength in which the galaxy has yet been
examined, so the published positions are all either estimates, or refer to
various other features within the galaxy. The position that I've adopted is
an estimated center of the bar as seen on the red DSS2 image. This position
is within about 20 arcseconds of a superposed "late G-type star" (according to
Lira et al, MNRAS 382, 1552, 2007, who have a spectrum).
=====
NGC 4239 is the only one of Pechule's five nebulae listed in AN 2710 to have
been listed in the NGC with a credit to him. In spite of his being a careful
observer with access to micrometers (he regularly measured planets, asteroids,
and comets at with the 11-inch Merz refractor at Copenhagen through the latter
part of the 19th century), he gave only crude positions for the nebulae (0.1
min of time and 0.1 deg), estimated from the BD charts. That for N4239 is
nevertheless within two arcmin of the modern position.
Dreyer credited two of Pechule's nebulae only to Borelly (NGC 3933 and 3934);
this is probably a good thing as Borelly's positions are much better. And the
remaining two nebulae in Pechule's paper are not in NGC at all. They did not
enter the catalogues again until they were picked up for CGCG and MCG: CGCG
098-033 = MCG +03-31-025 and CGCG 098-035 = MCG +03-31-027 = UGC 7032.
Pechule has only a single position for these two along with a comment that
they are possibly no more than stars. I suspect that this is why Dreyer
skipped them.
=====
NGC 4240 = NGC 4243, which see.
=====
NGC 4241 = IC 3115. See NGC 4223 = IC 3102.
=====
NGC 4243 = NGC 4240. Swift's declination is 1 deg 22 arcmin too far south,
but his description makes it entirely clear which object he saw. There are no
other galaxies in the area with a similarly bright star just 30 arcsec west.
Tempel and Common described the galaxy/star pair the same way. Tempel
actually saw the object on four different nights, finally measuring it on 24
May 1881. This is position that Dreyer adopted for the NGC 4240 entry.
=====
NGC 4244. What I had previously taken as a superposed star near the center of
the bulge of this large, nearby, edge-on galaxy is, in fact, the nucleus (see
e.g. Seth et al, AJ 129, 1331, 2005 and Seth et al ApJ 687, 997, 2008). HST
images clearly show the elongation of the rotating nucleus, so it is obviously
not a star in spite of its classification as one based on the SDSS spectrum,
or in spite of its appearance as one based on survey images.
Consequently, I have adopted the position of the nucleus as the position of
the galaxy.
=====
NGC 4246 = IC 3113 (which also see). In a note in the NGC, Dreyer defends the
use of the declination from a Harvard observation by G. M. Searle rather than
from WH's single observation. As it happens, Searle is correct. The RA is
only five seconds out, so the identity with IC 3113 is solid. Since there are
other NGC objects in the area that Schwassmann did not identify as such (see
e.g. NGC 4223 = IC 3102), I am beginning to think that he had a reason to omit
the numbers from his table. Perhaps the confusion explained in the note about
N4223 above had something to do with it. I'll have to dig into Schwassmann's
text a bit to see if anything obvious falls out.
=====
NGC 4248 is a peculiar, low-surface-brightness galaxy -- perhaps an I0 or a
peculiar dwarf spiral, quite nearby in the Ursa Major I Cloud. It has no
obvious nucleus, though it does have several stars, presumeably supergiants,
and knots scattered across it. There are a few superposed stars as well. The
rest of the galaxy shows incipient resolution in the SDSS image.
The position I've adopted is from SDSS; it seems as good as any, and is
centered on one of the bright stars in the dusty central part of the galaxy.
=====
NGC 4250. This galaxy also carries the designation "NGC 4250A". This was
assigned by Philip Keenan in a 1935 paper (ApJ 82, 62) where he listed
"approximate positions" for 32 "previously uncatalogued nebulae". See IC 381
for another previously catalogued example from this paper.
Keenan gave the "previously uncatalogued" galaxies names based on the nearest
NGC galaxy, with suffixes attached to differentiate them from each other.
This is perhaps the earliest use of suffixed NGC numbers, and set a bad
example that others have followed through the years.
=====
NGC 4254 = M 99. See NGC 4579.
=====
NGC 4263 = NGC 4265, which see.
=====
NGC 4265 = NGC 4263. WH looked for his galaxy a second time, but could not
find it. JH suggested that it might have been a comet. I doubt that Swift
was aware of this -- his position is so close to WH's in the GC that he almost
certainly just overlooked the GC entry.
Howe settled the matter when he wrote in his second Monthly Notices paper, "I
saw only one nebula here." Dreyer took this to heart and set the two numbers
equal to one another in the IC2 Notes, in his 1912 Monthly Notices list of NGC
corrections, and in a note in his edition of WH's Scientific Papers.
Curiously, Dreyer seems to suggest that we use NGC 4265 instead of NGC 4263.
I don't see why we should -- this is Swift's error, not WH's.
Finally, I note that Bigourdan also looked for two galaxies here, but found
only one. Unlike Dreyer, he adopts the number derived from WH's observation.
=====
NGC 4279. See NGC 4280.
=====
NGC 4280 may be the short line of three stars between N4279 and N4285. Swift
has it as the "2nd of 3," but there are only two galaxies here. Howe calls
them N4280 and N4285, but modern catalogs (including SEGC) have made them the
two outer objects of the triple Swift claimed to have seen.
Unfortunately, he has no notes about stars in the area, so we are left only
with his poor positions and inconsistent descriptions of brightness (he calls
the last of the three the brightest; Howe noted correctly that it is actually
fainter than the preceding galaxy). There are also no systematic offsets in
the positions of the other galaxies he found the same night (see also N6059),
so we can't recover the missing nebula that way.
So, the only faintly reasonable explanation is that Swift's middle "nebula"
is the line of stars, but this is little more than a guess.
=====
NGC 4284 may also be IC 3166, which see.
=====
NGC 4285. See NGC 4280.
=====
NGC 4286 = IC 3181, which see.
=====
NGC 4290 may also be IC 3180. See IC 3166 for the story.
=====
NGC 4292. See NGC 4301, as well as NGC 4292A in the "notngc" files.
=====
NGC 4294. See NGC 4368.
=====
NGC 4296. See NGC 4297.
=====
NGC 4297. Though noted as not found by d'A and Reinmuth, this galaxy is
indeed where WH found it: "... close by ..." N4296. It is actually north,
and just a bit preceding the larger, brighter galaxy. It is very faint,
though, and very small, so I'm not surprised that d'A did not see it. It
probably appears stellar on the Bruce plates that Reinmuth examined.
=====
NGC 4301 is one of the "classic" cases of a problem NGC object. People have
been puzzling over it since Bindon Stoney found it on 1 March 1851 with LdR's
Parsonstown Leviathan. Sue French just (May 2006) asked about it, so I am
finally digging into the records to find out what I can about it. I must
mention, too, that Malcolm Thomson has made valuable contributions to solving
this puzzle. More on that as we go along. (There is a bit more in the
"notngc" files under NGC 4292A.)
Here is the story:
In his 1861 paper, LdR has NGC 4292 and NGC 4303 listed together as having
been observed five times. He continues,
Sketched 4 times. March 1, 1851. [h]1196 [= N4292] is bM and has a vF
comp.; [h]1202 [= N4303 = M 61] is a spiral, B. centre, and 2 knots. There
is another neb. 10' nf.
Here's the first bit of confusion. Is the nebula 10 arcmin northeast of N4292
or N4303? LdR's note can be read either way. I'll lay out some arguments
below suggesting that it is northeast of N4303 and not N4292 as many,
including Dreyer himself, have supposed.
A second bit of confusion follows immediately, still apparently in the same
observation of N4292 and N4303:
About 84[deg] 34' N.P.D., and 12h 25m AR. There is a scarlet * 10m. and a
F. E. neb. 10' s. of it, with *s in it. See fig. 21, Plate XXVII.
This comment turns out to be totally unrelated to N4292 or N4303; it applies
instead to NGC 4480. But LdR finishes up this section of his Description with
his note about the figure. I should note here that LdR misidentifies the
figure, calling it "h1196" while it is really M 61 = h1202.
Finally, he finishes the comments on N4292/N4303 with
April 9, 1852. Last year's observations confirmed.
So, LdR gives us two new nebulae in his 1861 monograph: a very faint
companion for NGC 4292 (NGC 4292A; see the brief comments about this in the
"notngc" files), and another nebula 10 arcmin north-following either N4292 or
N4303. And he initiated a chain of confusion with his two errors and the one
ambiguous statement.
JH received the monograph soon after it was published, in time for him to scan
it thoroughly for the GC which he was then preparing. His note in the GC
shows that he took LdR's published description at face value:
[GC]2884 1202,a. Under h. 1196 and 1202, two nebulae, unidentifiable, are
described as companions, but there must be some great error in Lord Rosse's
account of them, as the place of one is referred to a scarlet star "10
[arcmin] south of a scarlet star R.A. 12h 25'[sic]." Now h. 1202 is in R.A.
12h 14m. To afford a fair chance of reobserving them, the companion 10' nf
h. 1202 is entered here as 1202,a, and that south of the scarlet star, under
No. 3060 as 1196, a."
His entries in GC are credited as "R. nova?" and "R. nova", respectively, so
he apparently placed greater reliance on the observation of the nebula south
of the scarlet star.
The next observers trying to find nebulae here were d'A and Schultz. Neither
were successful. d'A's note is in Latin, and is available elsewhere on the
NGC/IC Project's web site; Schultz merely says "GC. 2884. Not a trace of it
discernible."
The next mention of the field comes from Dreyer himself in two notes in his
1878 Supplement to the GC. The first is for GC 2884 which became NGC 4301
itself:
Not found by D'Arrest (Query, did he search "10' ad austrum" instead of 10'
nf?). Not seen by Schultz. There is not any "great error in Lord Rosse's
account." The Nebula south of the scarlet star ([GC] 3060) was seen after
h. 1196 and 1202 had been observed, probably while the telescope was being
moved back to the meridian.
He is arguing that LdR's description is not at all misleading and that JH
simply misread it. I'm siding with JH on this one; the comment about NGC
4480 is just out of place, and is too easy to read as JH did, and as I first
did. It clearly needed its own entry in the 1861 monograph.
However one reads the note, Dreyer continues with another in the GC Supplement
that gives some further details on the interpolated observation:
[GC] 3060. To be struck out, = h. 1299 ([GC] 3032) [= NGC 4480], the star
is B. W. 12h 378 (Sch. red star 148).
JH and I would have appreciated having this information in the 1861 monograph.
The next information comes just two years later in LdR's 1880 monograph,
prepared, of course, by Dreyer himself. Four observations are assigned to
NGC 4292 (GC 2870 = h 1196; in what follows, the square brackets enclose
comments by Dreyer, and appear just as I have typed them in here):
1851, Mar. 1. bM and has a vF companion [2' n by a diagr].
1851, Apr. 21. Another neb 10' nf. [Entered as a nova (2884) nf h 1202 in
the G.C., but nothing was found there by d'A. and Schultz. The place 10'
nf h 1196 does not appear to have been examined by anyone yet.]
1861, Mar. 17. (F Moonlight.) About 15' p and 8' n is a F neb with a * or
Nucl in centre and a * 8m close on its np side.
1878, Mar. 28. F, S, R, vglbM. *9m Pos. 333[deg].7, Dist. 72".3. 16'+- n
and 9'+- p is a vF object, sbM, most probably only a F *, it has a * 8.9m
np v nr. (IV. obs.)
Let's take these one by one. The 1 March 1851 observation is correct as far
as I can tell -- the vF companion is 2.4 arcmin north of NGC 4292. This is
the first of LdR's "novae" in this field that should have been in GC and NGC,
but were omitted (as noted above, this is NGC 4292A and is discussed briefly
in the "notngc" files).
The 21 April observation probably applies to NGC 4303. While there is a
galaxy (UGC 7411, m_B = 14.9) north-northeast of NGC 4292, the actual distance
is 11.9 arcmin. This compares with UGC 7439 (m_B = 14.1) at 9.6 arcmin north-
east of NGC 4303.
On 17 March 1861, LdR says nothing about the galaxy itself, but notes another
faint nebula 15 arcmin west and 8 arcmin north. There is nothing at all at
those offsets; in particular, there is no star 8 in the area. The north-south
distance between N4303 and N4292 is 7.5 arcmin, so I wonder if this is an
observation of N4303 with a slightly erroneous description of N4292 -- which
does indeed have a brighter star "close on its np side."
Finally, Dreyer's own observation on 28 March 1878 is pretty clearly of N4292
-- except that again there is no object 16 arcmin north and 9 arcmin west with
a star 8-9 magnitude "np v nr." Is this yet another garbled observation of
N4303, but this time mixed in with a real measurement of N4292 and its nearby
star? I measure a separation of 71 arcsec at a position angle of 335 degrees,
very close to Dreyer's more precise measures. The note "(IV. obs.)", by the
way, is just the total number of observations of the object.
This raises an interesting point about NGC 4303 (= GC 2878): Dreyer has the
note "(VII. obs.)", but only lists three of them:
1851, Mar. 1. Spiral, 2 knots, centre B.
1851, Mar. 7. Drawn [P.T. 1861, pl. XXVII., fig. 21, both on the plate and
in the G. C., p. 42, this figure is erroneously stated to represent h
1196].
1878, Mar. 28. Neby E ns, branch from s end turning p towards a * 13.14m in
Pos. 254[deg].3, Dist. 70".9. (VII. obs.)
All of these, including the correction to the figure captions, clearly point
to NGC 4303. But where are the other three observations? I've not been able
to find them in the published monograph. If the observing notes of the third
and fourth Earls of Rosse are still extant, we might be able to do a search
for the missing observations.
(Just to cover all the objects thoroughly, here are the 1880 monograph
descriptions on NGC 4480 = GC 3032 = h1299 = H II 531:
1851, Apr. 21. At 84[deg] 34'+- and 12h 25m+- I found a scarlet * 10m. and
a F, E neb. 10' s of it, with st[s] in it.
1852, Apr. 9. About 12h 23m and NPD 84[deg] 43' there is a ruddy (not
scarlet) * 10m. and a F neb. 10' s of it. [As already pointed out by d'A,
this neb is = h 1299 and the * = B.W. 12h, 378, Schj. red stars No. 148.
G.C. 3060 is to be struck out.] (II. obs.)
This is a fair description of NGC 4480 and HIP 61022, V_Tycho2 = 8.33,
(B-V)_Tycho2 = 1.43, indeed a red star. So, here at last is the information
that JH needed to have in the 1861 monograph to correctly identify the object
inserted willy-nilly into the descriptions for N4292 and N4303.)
At last we come to the NGC where Dreyer's note reads
4301. The place of 2884 is wrong in G.C., as the nova is 10' nf of h 1196
and not of h 1202. It was therefore not found by d'A and Schultz.
Dreyer adjusted the position of NGC 4301 appropriately, and most people have
taken the entry to point to UGC 7411.
I certainly did this for years until Malcolm pointed out the inconsistencies
and errors in LdR's two monographs. So, I now think that the evidence points
to UGC 7439 as the correct object. It is twice as bright and considerably
larger than U7411, as well as closer to N4303 than U7411 is to N4292 -- and
therefore more likely to be noticed. As for d'A and Schultz not being able to
find it -- they were using 11-inch and 9.6-inch refractors, respectively.
These would allow them to dig out the Herschel's objects, but -- with all due
respect -- not objects discovered with a 72-inch reflector.
So, to summarize. I think it is likely that Lord Rosse's garbled observations
point to UGC 7439 (sometimes called NGC 4303A in modern catalogues) as NGC
4301. I've put colons on this object.
However, it is just possible that Lord Rosse saw UGC 7411. Even though this
is 0.8 magnitudes fainter, and half the size of UGC 7439, he could still have
run across it -- many of his discoveries are considerably fainter, including
the tiny galaxy just north of NGC 4292. So, I've put U7411 into the position
table with question marks as a caution that this case is not entirely closed.
=====
NGC 4303 = M 61 = h1202 = H I 139 is one of the few Messier objects to also
carry a number in WH's lists. It also figures in the identifications of NGC
4301 (which see, along with the short entry on NGC 4292A in the "notngc"
files) and M 91, which see under both NGC 4548 and NGC 4579.
=====
NGC 4305. The position given for this by Schwassmann in his list of Virgo
Cluster galaxies is about an arcmin off to the south of the true position.
Since Schwassmann was a pioneer in the measurement of accurate positions on
photographic plates, this -- and a few other buggy numbers in his list -- are
a bit of a puzzle. They most likely come from numerical errors in the
reduction of the measured rectangular coordinates to RA and Dec. In our
present age of electronic computers, we often forget that the calculations at
the turn of the century were all done by hand. Accidental errors were thus
more likely. My guess is that this is one, though it may, of course, come
from any number of sources including measuring error, simple transcription
error, and so on.
See also NGC 4443.
=====
NGC 4306. In the NGC, this is credited only to d'A who found it on 16 April
1865. However, Steve Gottlieb points out that the galaxy was actually first
seen by Johnstone Stoney on 13 April 1849 with LdR's big telescope. The
galaxy is labeled [beta] on Stoney's sketch, and he describes it (along with
NGC 4305, which see for another story) as "... nearly in merid, both F, alpha
[N4305] the larger ...". Dreyer apparently overlooked Stoney's priority when
he was assembling the NGC.
Another case from this same observation by Stoney is NGC 4402, whch see.
See also NGC 4443.
=====
NGC 4310 = NGC 4338, which see. Also see NGC 4311 and NGC 4317.
=====
NGC 4311. JH has only one observation of this, calling it "Faint; the
south-following of two." The "north-preceding" of the two is N4310 which
JH called "Very bright."
There is only one galaxy here, N4310, and that was also seen by WH, as well as
by JH during the sweep previous to the one during which he saw two objects in
this place. It is possible that JH misidentified another pair -- but there is
no other pair near his place, nor at any reasonable digit error from his
place. In addition, his measured position for N4311 is less than 20 arcsec
from the single galaxy here. This is would be a remarkable coincidence if the
position actually applies to another object.
So, we are confronted with another lost NGC object.
=====
NGC 4313. See NGC 4368.
=====
NGC 4314. See NGC 4317.
=====
NGC 4315 may be one of the two 13th magnitude stars south of NGC 4316. Tempel
mentioned the object in his descriptive note that accompanies his micrometric
position for NGC 4316 in his fifth paper including new nebulae. In that list,
he places N4315 at 2 seconds preceding and 1.5 arcmin south of NGC 4316 --
there isn't anything there. The brighter star is at the required declination
offset, but its RA is about 3 seconds larger than N4316's. This would require
that Tempel made a mistake in the sign of his RA offset. This isn't unknown
-- see NGC 4186 for another example.
The fainter star is another candidate. The RA offset is in the right
direction (it is 3 seconds preceding the RA of the galaxy), however, it is
nearly 3 arcmin south of N4316, not 1.5 as Tempel made it. So, I feel that
this is less likely to be his object (though it is the one that I chose the
first time I went over the field without Tempel's paper at hand).
In either case, Tempel has mistaken other stars near other galaxies as
nebulous (see e.g. N577, N4322, N4327, and N4768/9), so having one near N4316
is no surprise.
=====
NGC 4316. See NGC 4315.
=====
NGC 4317 is lost. WH's observation (this is II 324) fits in order with the
rest of the nebulae he found the same night 13 March 1785, many of which were
compared with 13 CVn (= 37 Comae = SAO 63288). II 324 has the same RA offset
as I 76 = N4314, though is supposed to be 1 deg 9 arcmin north of that galaxy.
There is nothing at WH's position.
A possibility for WH's object is NGC 4310 = NGC 4338 (which see). It is at
roughly the correct RA (17 seconds preceding WH's), but is 1 deg 50 arcmin
south of WH's Dec. This makes it unlikely that this is the object he saw.
Finally, Reinmuth, RNGC, and Steinicke have called N4317 a star. I think this
is unlikely as WH would have probably noted the object "very small" or
"extremely small" rather than simply "small."
=====
NGC 4319 = NGC 4345, which see.
=====
NGC 4320. Is this possibly also NGC 4368? See that for the speculation.
=====
NGC 4321 = M 100. See NGC 4322, NGC 4323, NGC 4327, and NGC 4579.
=====
NGC 4322 is probably a star. It, NGC 4323, and NGC 4327 were all found by
Tempel while he was observing NGC 4321 (M 100) and NGC 4328. He only gives
descriptive places for them with respect to the brighter objects, so the NGC
positions are only approximate. His entire note for the three objects reads
(translation by me), "... on my drawing, there are three other very faint
nebulae in the vicinity, two north of and close to 2890 [N4321], and the third
south of 2894 [N4328]."
Given Tempel's propensity for seeing nebulae where only stars exist, I think
that the star northwest of M 100, and one of the stars southeast, along with
the galaxy to the northeast, are Tempel's three objects. It's certainly
possible to argue with this since Tempel gives no details about the appearance
of his objects, but this is a reasonable hypothesis under the circumstances.
The galaxy to the northeast has been called "NGC 4322 = NGC 4323" by many
observers. Since Tempel's description is very clear about his having seen two
"nebulae" north of M 100, the identity cannot be true. This has the
unfortunate consequence that the number 4322 is put onto a star, but I prefer
this to inverting the RA order.
=====
NGC 4323 is the galaxy northeast of M 100 (= NGC 4321) that has been called
"NGC 4322 = NGC 4323" in many catalogues and lists. See NGC 4322 for the
story on this.
=====
NGC 4325 is probably also NGC 4368, which see.
=====
NGC 4327 is perhaps one of the two stars near NGC 4321 and NGC 4328 listed in
the table. I don't see anything else "south of [N4328]" that Tempel might
have included in his sketch. See NGC 4322 for more details.
There is what appears to be an asterism of four stars on the POSS1 version of
DSS near the nominal position for N4327. This is in fact a single star with a
group of four plate defects superposed. Malcolm noticed this, and I'm
grateful that he called my attention to it.
=====
NGC 4328. See NGC 4322, NGC 4323, and NGC 4327.
=====
NGC 4332. See NGC 4512.
=====
NGC 4336 = IC 3254, which see. Frost must have thought that IC 3254 was a new
object as he measured its position to be over 2.5 arcmin away from that for
NGC 4336. The GC/NGC position itself, from JH's two observations, is even
further. (D'Arrest's position is within a few arcsec of the modern position,
but JH did not get a copy of d'A's monograph in time to cross-check the GC
positions.)
In any case, as I explain in the story for I3254, the identity seems likely,
so I've adopted it for the main table.
=====
NGC 4338 = NGC 4310. d'A's RA is just one minute following NGC 4310, and his
description is apt. Also, he measured N4310 on three nights (his numbers 80,
164, and 380), and N4338 on only one other night (night 110). This makes it
almost certain that his RA on that one night is just one minute too large.
=====
NGC 4341 = IC 3260, NGC 4342 = IC 3256, and NGC 4343. There is a group of
five galaxies here to which three NGC numbers and four IC numbers apply.
Needless to say, the identifications are pretty thoroughly scrambled in the
literature. Here is the story:
William Herschel (1786) saw three objects (III. 94-96) here, but gave only one
position for the them. John Herschel included only one of the objects in his
1833 catalogue, calling it "III. 94," the first of the three numbers
assigned by his father. When he prepared the GC, he used his position for
this brightest object, but his father's position for the other two, thus
giving the lowest of WH's numbers to the object with the largest right
ascension. Dreyer used a mean value of JH's position and one from d'Arrest
(1867) for the brightest object, but still had only WH's positions for the
remaining two. Thus, the inverted order of WH's numbers remains in NGC, with
the largest NGC number (4343) receiving the smallest WH number (III. 94).
In sorting out the NGC numbers, I've simply assumed that WH saw the brightest
three galaxies here, and that JH and d'Arrest measured the brightest one of
these. These three galaxies also have the highest surface brightnesses of the
five objects in question, so this is an entirely reasonable assumption to
make (see RC3 for the data). This means, however, that the brightest object,
NGC 4343, has the smallest right ascension on the sky, but the largest RA in
NGC. Also, I've followed RC1 (and most other modern catalogues) by assigning
N4342 to the middle of the three galaxies, and N4341 to the remaining
(following) object, thus retaining the reverse order.
Bigourdan's observations of 1895 and 1907 of all five objects here yielded
four numbers in the second IC. Schwassmann measured four of the five objects
on a Heidelberg plate (the fifth object that he did not measure probably
appears stellar on the plate). Dreyer used these four accurate positions in
IC2; this has led Herzog (1967 and CGCG) to suggest dropping the questionable
NGC numbers altogether, and simply use the unambiguous IC numbers instead.
RC2 and RC3 adopted this solution.
However, this discards two NGC numbers which we can now assign based on modern
photometric data. So, I have adopted the identifications suggested here.
Appendix 6 in RC3 is a table of most known identifications for all five of the
galaxies. The curious are referred to it for cross-references into the modern
literature and catalogues. You should also see NED for the new names added to
these galaxies since 1991.
=====
NGC 4342 = IC 3256. See NGC 4341.
=====
NGC 4343. See NGC 4341.
=====
NGC 4345 = NGC 4319. This was found by J. G. Lohse with Mr. Wigglesworth's
15-inch refractor. Lohse's position (which has nothing in it) is just a
minute of time following N4319, and his description fits the galaxy. Since
Lohse does not mention N4319 in the observation, this is almost certainly
identical to it.
Carlson called N4345 a star, an identification picked up by RNGC. I think it
very unlikely that a star would be mistaken for a "F, pL, gbM" nebula in a
15-inch telescope. The more likely explanation is simply a 1 minute error in
the RA.
=====
NGC 4347 may be NGC 4348, or it may be the star noted in the position list.
There is another fainter star to the southwest of the brighter one that may
play a role in this object, too.
This was found by Peters, included on his charts, and published as a "nova"
in his first list of positions. He notes there that the object "... hardly
can be G.C. 2911 [N4348] ...; but upon my chart I find no nebula drawn in this
place." At the end of his second list, he appends this note, "The note to
Nova 12h 16m42s; -2d 27.7m [1860.0] should be cancelled, as on 1881, May 5, I
have seen and drawn upon my chart also the nebula G.C. 2911."
It is still possible that the N4347 = N4348 -- Peters never says that he saw
both nebulae at the same time. Nevertheless, that is his clear implication,
so the equality is a possibility, no more.
I'm slightly more inclined to the notion that he somehow mistook the two stars
as a nebula. Whether this is true or not may never be known as both objects
must be shown on his charts. Whatever the case, there is certainly no nebula
at the position Peters gives for NGC 4347.
=====
NGC 4348 may also be NGC 4347, which see.
=====
NGC 4349 is a large, rich cluster embedded in the plane of the Milky Way. JH
has three observations of it; in one, he makes it 10 arcmin across and puts
the position northwest of a 9-10th magnitude star. For the other two, he says
it "fills the field", and he gives the position of that bright star, but notes
that is indeed southeast of the center.
I've estimated the center to be two arcmin north of that star, and see it as
an elliptical cluster of stars, 16 arcmin by 11 arcmin, elongated in PA = 135
degrees. This seems to be more or less what JH was describing. Whether it is
a real cluster needs to be determined by a careful study of the stars in the
area. My guess is that the core really is a cluster, but that many of the
stars in the outskirts are just random field stars.
=====
NGC 4351 = NGC 4354, which see. See also NGC 4367.
=====
NGC 4352. See NGC 4368.
=====
NGC 4353 = IC 3266. Peters's position is not very good. That led Schwassmann
to miss the NGC number when he picked up the galaxy in three of his 6-inch
plate zones from Heidelburg. Still, Adelaide Ames caught the identity when
she prepared her Virgo Cluster catalogue in 1930. However, CGCG muddied the
picture again by calling the galaxy "I3265 = I3266 (= N4353?)". IC 3265,
which see, is a star north-northwest of the galaxy.
The nucleus is quite faint; this has made it difficult for the centering
algorithms of the automated surveys to find an accurate position. I have
finally chosen the GSC-A position. That seems to pretty well represent the
galaxy.
=====
NGC 4354 = NGC 4351. Swift's position is only 5 seconds of time following
N4351, and his note "in vacancy" makes the identity virtually certain. Had
there been another galaxy nearby, Swift would have noted that instead.
The identity was first suggested in one of the Harvard papers (Dreyer has an
IC2 Note that Frost did not find the object on a 4-hour plate), and was copied
into Carlson's 1940 paper. RC1 and RNGC picked it up from there.
=====
NGC 4355 = NGC 4418. This is one of the 30-odd nebulae that David Todd ran
across during his search for "the trans-neptunian" planet in 1877 and 1878.
He estimated very crude positions for most of them using the setting circles
on the USNO's 26-inch refractor. Fortunately, he also gave us sketches of the
star fields around each of the objects and, often, measurements of RA
differences between the stars and the nebulae.
Unfortunately, these were not enough to allow Dreyer to identify the objects.
Dreyer included in the NGC some objects that he thought might be "novae", but
he skipped others that seem, to me, just as likely to be included -- and that
were, in fact, new nebulae.
In any event, Dreyer did include Todd's 17th nebula as NGC 4355. Using the
sketch of that nebula's field, it's easy to see on the Sky Survey prints/films
(even in a DSS field at least 15 arcmin on a side) that it clearly refers to
NGC 4418. See NGC 3604 for more about Todd's search.
=====
NGC 4356 = IC 3273, which see.
=====
NGC 4357 = NGC 4381, which see.
=====
NGC 4358, and NGC 4362 = NGC 4364. All three numbers are credited to WH, who
recorded them as follows on 17 April 1789:
WH delta RA delta Dec Star Desc
III 799 1m 12s p 1d 36m n 71 UMa vF, vS
III 800 1m 09s p 1d 37m n 71 UMa }
} Two, both cF, cS, R.
III 801 " " " " }
The "lE" notation in NGC comes from John Herschel, who observed only two of
these on 1 May 1831:
JH WH RA (1830) NPD Desc
1230 III 799 12 15 42.1 30 40 32 F, lE, the p of 2
1233 III 800 12 15 50.1 30 41 32 eF, the last of 2 (the
other was III 799;
III 801 not seen).
Note the relative positions, "p of 2" and "last of 2." These notes about
the positions should take precedence over any comments about shape since
apparent axis ratios depend on the limiting isophote of a galaxy (the deeper
the isophote, the rounder a galaxy appears).
This is how matters stood when JH put together the GC. There he assigned
three numbers (GC 2914, 18, 20) assuming that all three objects existed, and
added a comment about the RA of the first possibly being a minute later than
listed. I've not been able to track the source of this comment, as all the
positions measured up to that time are pretty much in agreement.
The other pre-NGC observation was by d'Arrest, who also saw only two objects
here (on 4 Oct 1866):
h H RA (1860) Dec
1230 III 799 12 17 28.1 +59 09 38
1233 III 800 12 17 32.1 +59 08 02
d'Arrest's descriptions and comments are all in Latin which I don't read. I
can make out the comment "III 800 is south-following" in the description for
III 799, and there is a four-line note about III 801 in the description for
III 800 (which also mentions the star just to the south).
Unfortunately, Lord Rosse and his observers did not look at these galaxies.
Based on JH's work on the GC, Dreyer again assigned three numbers. Later
(WH's Scientific Papers, and MN 73, 37, 1912), he noted: "Very probably the
word `two' refers to III 799 and III 800, as nobody seems to have seen three
nebulae in the place."
Both Bigourdan and Reinmuth also only saw two of the three -- though Bigourdan
claimed to have missed N4362 while Reinmuth could not find N4364 -- so that
has added to the confusion.
As Glen (Deen) noted, there are indeed three galaxies here; all are mentioned
in CGCG (only two entries, but the north-preceding is a pair), MCG (all
three), and UGC (the brightest is UGC 7479; the other two are in the Notes).
RNGC, of course, assigns one number to each galaxy (but not the ones you might
expect; more below).
Modern data for the three galaxies are as follows:
RA (B1950.0) Dec D d m(p) CGCG MCG Other
12 21 34.56 +58 39 27.5 0.3 x 0.2 16.9 293-017w +10-18-037 NPM1G +58.0113
12 21 39.15 +58 39 43.7 0.9 x 0.7 14.4 293-017e +10-18-038 UGC 7479
12 21 48.45 +58 38 15.6 0.7 x 0.4 15.2 293-018 +10-18-039 ---
Positions are from GSC, diameters are my own measured on POSS, and are roughly
at the 25th mag/sq arcsec isophote. Magnitudes are from the CGCG. For
293-017 which has a combined magnitude of 14.3, I've assumed that the surface
brightnesses of the two components are equal, and have simply apportioned the
combined magnitude according to the ratio of the areas of the galaxies (the
first covers 9% of the total area covered by both, so has 9% of the total
light, etc.).
In short, these numbers support Dreyer's contention that WH actually saw only
two galaxies -- the third is most likely much too faint for WH to have seen
(JH, d'Arrest, and Bigourdan, using similar-sized telescopes, certainly did
not see it; it was also apparently not recorded on the plate which Reinmuth
examined).
Therefore, only the two brighter galaxies get NGC numbers. Since it is clear
that the relative orientation seen by everyone (except WH) is nw-se, the nw
object must be h1230 and the se must be h1233. Since Dreyer has assigned these
to N4358 and N4362, respectively, the last number (N4364) is left by itself.
This one comes only from WH's description ("Two"). Since it is the last
number in the sequence of three, I propose that it be put on the 2nd galaxy.
Finally, RNGC did its usual hatchet job on the field, leaving a mess behind.
It put one number on each of the three galaxies, managing only one correct out
of the three:
N4358 = CGCG 293-017w -- wrong.
N4362 = CGCG 293-018 -- right.
N4364 = CGCG 293-017e -- wrong.
=====
NGC 4359. This galaxy is nearly edgewise and shows no obvious nucleus. There
is a knot at the northwestern end of the central "bar" that several of the
automated surveys picked up, but the center of the "bar" is best represented
by one of the 2MASS PSC positions. This is the one I finally chose for the
galaxy.
=====
NGC 4362 = NGC 4364. See NGC 4358.
=====
NGC 4364 = NGC 4362. See NGC 4358.
=====
NGC 4365. There is just the slightest whisper of a possibility that this may
also be IC 3281 (which see) -- but I did not write it loudly enough for you to
hear.
=====
NGC 4367 is probably the double star near d'A's position. In his description,
d'A has this 35 seconds following a brighter nebula also found by him. That
nebula is NGC 4351, and the separation is correct. Also, d'A has two
accordant observations of N4367, so it is reasonably clear that he saw a real
object, nebulous or not.
The second of the two stars is quite faint, though. This may account for
Frost's not finding any nebulosity at d'A's position on a 4-hour Bruce plate.
Dreyer, in an IC2 note, has this nebula among several that Frost did not find.
=====
NGC 4368 is probably NGC 4325. Dreyer notes that WH's "... RA is possibly
1 min too great (see under II 64 [= N4352]). Not found by Bigourdan." The
note for N4352 reads, "RA is 1 min too great. The same is the case with
several other nebulae observed this night (Sw 174, March 15, 1784) ..."
The actual differences between WH's RA's and the true RA's varies from about
40 sec to well over a minute for the seven objects mentioned by Dreyer (N3810,
N4067, N4294, N4313, N4352, N4371, and N4429). If N4368 is indeed N4325
(discovered by d'A), its difference is 1 min 28 sec, not an unreasonable value
considering the other errors. The declination is 1.5 arcmin different, well
within WH's usual observing errors.
I can only speculate about the source of WH's error, since it does not affect
every object observed in Sweep 174. Thus, it could be a correction due to
a mistimed comparison star -- but different affected objects have different
comparison stars. Or it could be that WH forgot to make the correction to
the center of the field for the objects -- but since his field was only 15
arcmin across, the largest correction could only be half that value, or a bit
less than 30 seconds of time at a declination of +10 deg. Also, this is a
necessary correction for every object which does not sweep across the field
center -- which is almost every object observed. I can't see WH forgetting
such an obvious correction for a few objects in a sweep, but not for most
others.
Whatever caused the errors, the fact that they exist is clear, and N4368 seems
to be affected.
Finally, there is also the faint possibility that N4368 is N4320 (also found
by d'A). However, that is fainter and smaller than N4325, and WH's Dec would
be off by 3.0 arcmin rather than the 1.5 arcmin to N4325. The RA would also
be further off, too, 1 min 40 sec, so overall, I do not think this is a strong
possibility.
=====
NGC 4371. See NGC 4368.
=====
NGC 4374 = M 84. See NGC 4443 and NGC 4579.
=====
NGC 4376 is a late-type spiral with considerable patchiness across its face.
There is a trace of a nucleus in the infrared images, though this may just be
another of the knots. Nevertheless, I've chosen it to represent the galaxy;
it's near the geometric center of the isophotes and gives an acceptable
position for the galaxy.
=====
NGC 4381 = NGC 4357. The equality was suggested by Dreyer, and confirmed by
Bigourdan who did not find N4381, but who did discover N4357 and made eight
observations of it on two different nights. Dreyer suggests a simple 1 minute
error in WH's RA. Since the descriptions match, the identity is almost
certain.
=====
NGC 4382 = M 85. See NGC 4579.
=====
NGC 4387. See NGC 4407 = NGC 4413, and NGC 4443.
=====
NGC 4388. See NGC 4407 = NGC 4413, and NGC 4443.
=====
NGC 4390 = IC 3320, which is probably also = IC 3319 (which see). WH's
position is enough off that the identity of the nebula was questioned by d'A
(he got it right). Dreyer adopted d'A's position. See N4398 for more on this
field.
=====
NGC 4393 is identical to neither IC 3323 (a foreground star) nor to IC 3329 (a
knot in the galaxy); CGCG is wrong. See the IC numbers for a bit more.
=====
NGC 4394. See NGC 4397.
=====
NGC 4395. See NGC 4399 which, along with NGC 4400 and NGC 4401, are HII
regions in NGC 4395.
=====
NGC 4397 is an asterism of three stars, located where Tempel saw it, "... 5
seconds following, 6 arcminutes north of II 55 [N4394]." I had earlier called
this an asterism of four stars, but I now (April 2015) see only three on the
DSS1, DSS2, and SDSS images. (The SDSS actually shows a fourth, but it is an
extremely faint red star, perhaps seen just above the plate limit of the
DSS2R. It certainly would not figure in Tempel's object.)
Another apparent asterism exists another three arcmin to the north -- but only
on the POSS1 red plate and, therefore, on the DSS. It looked real enough to
fool me, but Malcolm caught it. My thanks to him for letting me know about my
mistake.
=====
NGC 4398 is a star. d'A has only one observation of this, found while he was
looking for N4390 (which see). His description for N4398 includes mention of
two stars to the southwest: an 11th magnitude star 16.35 seconds preceding,
and a 13th magnitude star 11.60 seconds preceding his "nebula." Both stars
are there (the separations for 1950 are 16.58 seconds and 11.18 seconds, both
well within the error bounds of the expected values). So, the identification
is secure.
=====
NGC 4399, NGC 4400, and NGC 4401 are bright HII regions in NGC 4395. WH found
N4395 and N4401, the main body of the galaxy and the brightest HII region,
recording them as two nebulae under one number. Thus, the NGC has the WH
numbers given rather awkwardly as "V 29.1" and "V 29.2." Lord Rosse (or
his observers) found the other two objects, but did not measure their offsets
from nearby stars or the nucleus. Instead, they printed a diagram which can
be pretty easily related to the sky, in spite of some distortion. The lack of
offsets also allowed Dreyer to give only approximate positions for N4399 and
N4400. Lord Rosse's sketch of the field, however, makes the identifications
clear.
=====
NGC 4400. See NGC 4399.
=====
NGC 4401. See NGC 4399.
=====
NGC 4402. Here is another of the 11 galaxies seen by Johnstone Stoney on the
night of 13 April 1849 that Dreyer does not credit to "LdR" in the NGC (Steve
Gottlieb noticed the omission; see also NGC 4306). The galaxy is [eta] in the
sketch, and Stoney describes it like this: "... hollow in the middle, probably
a ring seen obliquely, F * n of its middle, seen best with the single lens..."
His comment "hollow in the middle" clearly refers to the dust lane, and the
star is indeed 1.3 arcmin to the north.
See also NGC 4443.
=====
NGC 4405 = IC 788, which see.
=====
NGC 4406 = M 86. See NGC 4443 and NGC 4579.
=====
NGC 4407 = NGC 4413. This came about because JH has two observations of this
(and NGC 4388 in the same sweeps) which he did not equate. N4407 comes from
the second observation and is described only as "The following of 2." His
description for N4388 reads, "vF, E, the p of 2, dist about 30 sec in RA."
He marks the RA of N4407 with two colons (very uncertain), and the declination
with a plus/minus sign. So, it is clear that he measured only N4388, and
simply estimated the position of N4407 from the preceding galaxy. The only
galaxy that JH could have seen roughly 30 sec following N4388 is N4413, so the
identity of N4407 is almost certain. The identity with N4413 was suggested at
both Lick and Harvard. Both are quoted in Carlson's 1940 list.
As a result of JH's observations, N4388 has two separate GC numbers (2949 and
2956). Curiously, Dreyer caught the identity of the GC numbers for N4388, but
not for N4407 (= GC 2968) and N4413 (= GC 2974). Perhaps he was a bit
confused by WH's observations here which (correctly) call N4388 the south-
following of a pair (with N4387) rather than the preceding of a pair with
N4413 as noted -- also correctly -- by JH.
=====
NGC 4409 = NGC 4420. WH found NGC 4409 (= III 17) on 23 Feb 1784; he has only
the one observation of it. He found NGC 4420 (= II 23) a month earlier on 24
January, and made a second observation of it sometime later. JH found N4420,
but not N4409, so speculated that "This (N4420) may possibly be identical
with III 17." Since there is nothing at all in either of WH's positions
(that for N4409 precedes the galaxy by 33 seconds and is 2.5 arcmin north; and
that for N4420 follows the true position by 14 seconds and is 3.8 arcmin
south), and since there are no other galaxies in the area that WH could have
seen, JH's suggestion is probably correct. Dreyer carried it over into the
NGC description, and from there, it was adopted by Reinmuth, Harvard, Carlson,
and RC1.
=====
NGC 4410. JH described this as "eF, vL, R, gbM; 2 1/2' diam" from a single
observation on 28 January 1828. But the pair of galaxies is just an arcminute
across. Did JH actually see one of the NGC 4411 pair (which see for confusion
of its own)?
I frankly doubt it. The surface brightness of the NGC 4410 pair is
considerably higher, and JH's position is much closer to them than to NGC
4411. There is also no problem in JH's position. The offset from the nearest
"standard" star in his sweep, 12 Virginis, is +12m 55s, -1d 15m 25s; so, the
reduced position for NGC 4410 is within 2 seconds of time and 6 arcseconds of
the position that JH himself reduced considering all the stars in the sweep.
This pair of galaxies is interesting in its own right as an interacting pair
with a very faint distorted corona. There is a bridge leading to IC 790 and
CGCG 070-079 beyond that, also connected by a bridge. All of the galaxies
have similar redshifts in the 0.023 to 0.026 range, so they are all part of
the same group.
=====
NGC 4411 = IC 3339 (which see) and "NGC 4411B." We know now that there are a
pair of low-surface-brightness spirals here, one at the position of NGC 4411 =
IC 3339, and the other at the position of Bigourdan 298 noted by Dreyer in an
IC2 Note for N4411. Dreyer, however, assumed the two positions to apply to
just a single galaxy, so there has been some confusion in the modern
catalogues as to which galaxy bears the number NGC 4411.
The solution I've adopted is to follow the historical positions -- Peters's
and Schwassmann's clearly apply to the preceding of the pair of galaxies --
as well as to give a bit of credit to Bigourdan for finding the second galaxy.
The slightly awkward numbering that apparently started with Holmberg in his
1958 monograph on galaxy photometry puts the numbers "N4411A" and "N4411B" on
the galaxies. This was adopted by the de Vaucouleurs for RC1, and persisted
through RC3 -- so we're probably stuck with it.
Still, as I said, it gives some credit to Bigourdan for digging out the
eastern galaxy. It is actually about half a magnitude brighter than the
western, though I think that the star superposed on the western might shield
the galaxy from sight in some circumstances or enhance it in others.
=====
NGC 4413 = NGC 4407, which see.
=====
NGC 4417 is not NGC 4437 = NGC 4517. A typo in Dorothy Carlson's list of NGC
corrections of 1940 is responsible for the confusion in some mid-20th century
catalogues. See NGC 4437 for more.
=====
NGC 4418 = NGC 4355, which see. N4418 itself has notes in the GC and NGC.
There is enough slop in the original position from WH, and enough of a
difference between his description and JH's, that JH was not convinced of the
identity between his nebula and his father's. In the event, he sorted it out
correctly, and Dreyer -- citing additional observations by Lord Rosse and
d'Arrest -- confirmed the identity.
The NGC 4355 label comes from an observation by David Todd. See the brief
discussion under that number, and under NGC 3604, for additional
identification adventures in Todd's list.
=====
NGC 4420 = NGC 4409, which see. See also NGC 4910.
=====
NGC 4424. See IC 793 and IC 3366.
=====
NGC 4425. See NGC 4443.
=====
NGC 4426 = NGC 4427 is a double star. This is one of the very few objects
which shows a bit of haste on Dreyer's part in his final work on assembling
the NGC. D'Arrest's and Bigourdan's positions and descriptions are clearly
pointing at the same object, and the two objects are adjacent in the NGC, yet
not until he saw the proofs did Dreyer add the note "These are evidently
identical (note added in press)."
In IC2, he has an additional note: "According to M. Wolf (list IV.) only
two stars 36 arcsec apart, n and s." The stars are actually separated by
only 13-14 arcsec, and Wolf's southern position points to empty sky -- this
may be a defect on his plate. In any event, there is no doubting the
identification as both d'A and Bigourdan have two observations of the double,
and both describe it as a small cluster, perhaps with nebulosity involved
(there is none).
There is a mistake in Bigourdan's notes, though his published position (in his
first Comptes Rendus list) is correct. He chose an anonymous comparison star
for NGC 4426, noting that it is "+1m 31s, -7 arcmin" from BD +28 deg 2116.
The correct distance in RA is -29.8s, so Bigourdan may have meant to write
-31s. Note, too, that Bigourdan came back to this after the NGC was published
to measure NGC 4426 on 17 April 1888. His earlier position for NGC 4427 is
from one estimate on 22 April 1886 with respect to NGC 4408 (which is 52s west
and 2 arcmin north according to Bigourdan). The descriptions for both
observations are virtually identical.
=====
NGC 4427 = NGC 4426 (which see) is a double star.
=====
NGC 4429. See NGC 4368.
=====
NGC 4430. See NGC 4453.
=====
NGC 4435. See NGC 4443.
=====
NGC 4437 = NGC 4517 with a 5 minute error in the RA. Reinmuth first suggested
the identity, but when Dorothy Carlson picked it up, a typo in her list made
N4437 = N4417. This was copied into RC1 where it hung on until I fixed it for
RC2. JH's description leaves no room for uncertainty about the
identification; he describes the galaxy and the nearby star perfectly.
His father's position and description are also appropriate for the galaxy and
star. Interestingly, WH lists it as the 5th of his class of "planetary"
nebulae, apparently because of the supposed interaction with the nearby star.
This shows that his classification system had not yet settled down early in
1784 when he first saw the galaxy. WH's reference to "Fig. 6", by the way,
points back to his 1784 paper, "Account of some Observations tending to
investigate the Construction of the Heavens," where he first discussed the
"stratum" of nebulae that we now call the Local Supercluster. This paper has
sketches of 15 of his nebulae and clusters, unfortunately poorly reproduced in
the 2003 reprinting of the Scientific Papers. Michael Hoskin's 1963 book
"William Herschel and the Construction of the Heavens" has a far better
reproduction of WH's sketches as its Plate 1.
The position I've adopted is for the stellar object near the center of the
bulge, just south of the dust lane. This may be a superposed star, but is
nevertheless at an adequate position to represent the galaxy.
=====
NGC 4438. See NGC 4443.
=====
NGC 4441. This galaxy is apparently a "merger remnant", the result of a
collision and gravitational merger of two (or perhaps more) galaxies. It's
central regions are patchy with dust and a few blue knots, and the inner
corona is disturbed. There are spectacular plumes and loops in the outer
corona that show up especially well on the blue DSS2 image.
Also see NGC 4512 where this figures in the identification of that galaxy.
=====
NGC 4442. See IC 793.
=====
NGC 4443 has usually been taken as a star following NGC 4435 and NGC 4438.
Exactly which star, I'm not sure as there is nothing at the NGC position aside
from a 19th or 20th magnitude object.
In any event, the only evidence we have for this object comes from one
observation in 1849 when LdR's observer, Johnstone Stoney, sketched it as the
last of 11 nebulae. The sketch is fairly crude and the distances between the
objects do not correspond well to what we see on the sky. Indeed, LdR himself
says, "Found the objects as in sketch, positions being put down very rudely."
Nevertheless, we -- and Dreyer who identified the objects for LdR's 1880
monograph -- can recognize the brightest galaxies in an east-west swath of sky
through the center of the Virgo Cluster. His objects are as follows (in his
order):
alpha = NGC 4305
beta = NGC 4306
gamma = NGC 4374
delta = NGC 4387
epsilon = NGC 4388
zeta = NGC 4406
eta = NGC 4402
lambda = NGC 4425
theta = NGC 4435
iota = NGC 4438
kappa = NGC 4443
As I noted above, there is nothing in the exact position of LdR's "kappa", but
NGC 4461 is not too far away. It is certainly not a big stretch to get to
this galaxy, and its description is a relative fit to the others.
The objection to this is that only one galaxy is shown in the sketch, whereas
there are, of course, two on the sky: NGC 4458 is not too far northwest of
N4461. Given the hurried nature of the observations, though, it may be that
Stoney thought N4458 to be a star. It is considerably smaller and fainter
than its companion, so this is a possibility.
So, I'm going to take N4443 to be a duplicate discovery of N4461, but with
some uncertainty.
=====
NGC 4445 = IC 793, which see.
=====
NGC 4446 and NGC 4447. I grumble and gripe about Swift's poor positions all
through these notes, but I do have to take my hat off to him for his keen and
practiced eyes. These two galaxies surprised me as I worked my way through
the many brighter objects in the plane of the Local Supercluster -- who could
have found these faint things?
Lewis Swift! He was using a 16-inch refractor that was apparently quite good
optically, and his observing location and techniques insured that he could
fairly often pick up 14th and even 15th magnitude galaxies. While it is true
that his positions for even these two lack the final polish of a micrometer,
they are good enough to insure that we can recover the galaxies today.
Unfortunately, the Mt. Wilson and Harvard observers saw the two positions
southeast of the pair and decided that both apply to the single brighter
southeastern object. Swift's description for NGC 4446 should set any such
concerns aside: "eeF, pS, R, ee diff; D, triplicity suspected; 2 = mag sts
range with it n and s; 3012 [NGC 4459] in field f." For NGC 4447, found the
same night (17 April 1787), he merely says, "eeF, pS, R; ee diff." (I think
he put the second galaxy in his 6th list to insure that it did not get lost in
the description for the first.) The note about the stars is not as clear as
it could be -- the two stars are directly north of NGC 4447 and are aligned
with the galaxy.
In any event, Swift certainly saw the two objects here, and gave us positions
just good enough to recover them.
=====
NGC 4451. See IC 793.
=====
NGC 4453. While there is probably no question about the identity of JH's
object, h 1283 (but see below), there is a problem with WH's (H II 26).
Dreyer notes in the Scientific Papers that the observations in Sweep 131 are
"very unsatisfactory" (a criticism that extends to Sweep 132 as well; see NGC
4577 for more). This was the only nebula found in Sweep 131, so there is
little to compare it with aside from the "unsatisfactory" observations of the
stars.
The galaxy that JH found is "eF" in his catalogue -- this does indeed match
CGCG 042-121 with V = 15.4 and B = 16.1 (SDSS) -- while WH's is "pB, pL,
brighter toward the following side." Dreyer suggests a possible identity with
NGC 4430, but that is 20 arcmin in Dec off the position of N4453 and 30
seconds off in RA. He also has a note from WH that there is a "very large
star" 9 minutes, 6 seconds preceding and 22 arcmin south of the nebula.
Assuming that N4430 is indeed WH's object, the description fits. But there is
no star at WH's offsets. The one that Dreyer suggests (BD +6 deg 2588) is
7 minutes, 29 seconds preceding, and 13 arcmin south. A somewhat brighter
star (HD 107258) is at 12 19 55.3, +05 40 18 (J2000.0) -- 7 minutes, 31
seconds preceding, and 35 arcmin south. Neither is a good match for WH's
offsets.
JH's much fainter galaxy (the one that we adopt as NGC 4453), however, is 9
min 0 sec following, and 28 minutes north of BD +6 deg 2588, a better --
though not prefect -- match to WH's observation. But the galaxy can hardly be
the one WH saw; it is far too faint, too small, and is not at all brighter
toward the east. There is also a double star a couple of arcminutes northwest
that could well be the object JH saw. The stars are considerably brighter
than the galaxy at V = 14.4, B = 15.1; and V = 15.0, B = 16.1; again, from the
SDSS.
At the end of all this, I'm leaning toward adopting NGC 4430 as II 26, though
with considerable uncertainty. At this point, you are probably asking "Why
bother? We know where NGC 4453 is." Knowing which galaxy is II 26 will help
with the puzzle of NGC 4577 = H III 13, found the same night, and supposedly
referred to the same star. See NGC 4577 for more.
=====
NGC 4458. See NGC 4443.
=====
NGC 4461 is probably also NGC 4443, which see.
=====
NGC 4464. See NGC 4471.
=====
NGC 4470 = NGC 4610, which see. This may also be IC 3281 (which also see),
but that is extremely unlikely. It is certainly not IC 3417 (which finally
see) -- that is a star 2.3 arcmin north of the galaxy.
=====
NGC 4471 is apparently one of the two stars flanking Schmidt's estimated
position given in AN 64, 1, 1865 (my thanks to Wolfgang for digging out this
paper). This is one of four "very faint and small objects" in the vicinity of
M 49 that Schmidt found and measured in the summer of 1861, and remeasured a
year later. D'Arrest points out (less than two months later in AN 64, 125,
1865) that three of the nebulae (N4464, N4470, and N4492) were observed by WH
and JH, and suggests that the fourth -- this one, N4471 -- is perhaps H II 498
(but that is NGC 4470; this was a confused field until LdR sorted it out --
see Dreyer's note for M 49 in the NGC). D'A goes on with his own observations
of the field, noting that he could find neither II 498 nor Schmidt's object at
their published discovery positions.
There is a considerably fainter compact galaxy about 1.5 arcmin on to the
northwest from the stars, but Schmidt has no other objects in his list that
are that faint. I doubt that he could have seen it with the 11-inch refractor
that he was using in Athens.
Finally, this is the only object without a micrometric measurement in
Schmidt's table of 27 stars and nebulae around M 49 (he also did not measure a
declination for one of the stars, but gives an RA). Precessing his positions
for the other nebulae, I found that the declinations are very good, but the
RAs are systematically too large by 0.6 to 0.7 seconds of time compared to
modern positions (the RA for his comparison star is perhaps affected by proper
motion). Unfortunately, this does not help us decide which star (if either)
Schmidt mistook for the nebula, as both are much further from his position
than this.
=====
NGC 4472 = M 49 is the brightest galaxy in the Virgo Cluster. See NGC 4471,
NGC 4486, NGC 4548, and NGC 4579.
=====
NGC 4480. See NGC 4301.
=====
NGC 4482 = IC 3427. WH's RA's for many of the objects in Sweep 174 on 15
March 1784 are too large by up to a minute of time. In this case, the error
is only 30 seconds. See IC 3427 for more.
=====
NGC 4485 is the irregular companion galaxy to NGC 4490. There is no obvious
nucleus, just a north-south string of blue knots across the middle of the
galaxy. The position for the galaxy that I've finally adopted -- from GSC-A
-- is just west of one of these knots.
=====
NGC 4486 = M 87 is the second brightest galaxy in the Virgo Cluster. NGC 4472
= M 49 is the brightest. Also see NGC 4579.
=====
NGC 4486A is an 11th magnitude star superposed on a 14th magnitude galaxy.
The SDSS and the 2MASS images show the two objects reasonably well-separated.
The individual positions are not very easy to determine; none of the automated
surveys have split the objects, so the resulting positions are dominated by
the brighter star.
=====
NGC 4486B is a prototypical red compact elliptical galaxy. Indeed, some might
argue that it is THE prototype of the class, close enough to be well-studied,
but far enough to appear nearly stellar in the various sky survey images.
Another similar galaxy, much closer to us, is M 32. Moved out to the distance
of the Virgo Cluster, it would appear very similar to NGC 4486B.
=====
NGC 4490. See NGC 4485.
=====
NGC 4492 = IC 3438, which see; and NGC 4471.
=====
NGC 4496. There are three galaxies in the printed edition of RC3 bearing this
number. One of these, VCC 1364 at 12 28 56.4 +04 14 54, has nothing to do
with the real NGC 4496 at 12 29 06.6 +04 12 54. This is the brighter of a
double galaxy, so is usually called NGC 4496A. Delete the NGC number from the
listing for PGC 41450 in RC3. Also delete T, L, B(T), and m'(25).
Also see NGC 5765 for a note about the objects noted as double by WH or JH,
but given only a single position.
Finally, see NGC 4505 for a genuine NGC mystery related to this galaxy, rather
than simple modern bungling.
=====
NGC 4497 is also IC 3452, which see.
=====
NGC 4501 = M 88. See NGC 4579.
=====
NGC 4505 is probably NGC 4496. Originally found by William Herschel on
23 February 1784, there is no trace of this on the sky. Yet John Herschel
claims to have observed it, too, and it is listed in Reinmuth's photographic
reobservation of the Herschel's nebulae. After that, however, it disappears
from the catalogues except to appear in errata lists. RC1, for example,
considers it to be identical to NGC 4496.
Sir William has only one observation of it, and that is referred to a
different star than his discovery observation of the nearby NGC 4496, of which
he has 3 observations altogether. His description of NGC 4505 -- "vF, cL, r"
is brief and could just be construed as a hurried observation of NGC 4496.
The positions are not that much different, either.
Sir John's single observation places NGC 4505 close to his father's position.
His description is even briefer: "eF; the f of 2 in the field." His right
ascension is marked "+-", so it is likely that we shall never know exactly
what he saw, but there are several faint stars near his place that he could
have mistaken for an "eF" nebula.
Reinmuth's extended description, "eeF, eS, R; = neb * or *14; *8 sp 7', *11.8
sp 2'; NGC 4505, *11.8, *8 in line" pinpoints a 14th magnitude star near Sir
John's place. This may be the star that Sir John himself saw and mistook for
a nebula.
We are left, then, with Sir William's lone discovery observation to explain.
Arguing against the equality with NGC 4496 are the different positions, and
the fact that both nebulae were found the same night. However, since
different comparison stars were used, it is indeed possible that the two
observations that night refer to the same object -- NGC 4496. Until Sir
William's original observing notes can be scrutinized, I'll adopt the identity
as a working hypothesis.
-----
Looking into this again after being directed to LdR's observation of NGC 4496,
I checked the sweep and found some very odd things there. This is 13th object
in the sweep (not counting a meteor), and is said to be 11' 45" following 16
Virginis and north by 38 arcminutes. Just a minute of time earlier, however,
is another nebula at exactly the same distance north of 16 Vir. Reducing
these observations gives positions about 30 seconds east and west of NGC 4496
where there is nothing on the sky. Assuming errors of 1 degree in recording
the NPD also leads to areas on the sky where there is nothing. Did WH somehow
manage to record NGC 4496 twice? The descriptions are suspiciously similar,
too. For the western object, he writes, "A faintish pL nebula, it seems to be
resolveable [sic]", and for the eastern, "vF of a consid size; it seems to be
resolvable [sic], is more F than the foregoing and rather larger."
Reading through the rest of the sweep also leads to some rather curious
circumstances. For instance, about 45 minutes before WH recorded these two
nebulae, he wrote, "An accident happened to the pulleys, but being set right
immediately, I suppose it has made no change, neither in time nor zero."
Other objects in the sweep referred to 16 Vir are
WH Position Modern Position W - M
RA (2000) Dec RA (2000) Dec DelRA DelDec
NGC 4409 12 26 25 +02 29.1 12 26 58.5 +02 29 40 -33.5 -34
NGC 4412 12 27 09 +03 57.2 12 26 36.1 +03 57 53 32.9 -41
NGC 4457 12 29 09 +03 34.2 12 28 59.0 +03 34 14 10.0 -02
NGC 4527 12 33 40 +02 37.4 12 34 08.4 +02 39 14 -28.4 -110
This is an early sweep, and WH was recording his objects with a precision of
only of 15 seconds. In this set of seven observations -- the star and the six
nebulae -- only 16 Vir, NGC 4409, and NGC 4527 were recorded to that accuracy.
The other four are given to a full minute of time only. It's no wonder that
their RAs are not very good.
In any event, all this convinces me that WH somehow did in fact record
NGC 4496 twice in the sweep, once ahead of its true meridian passage, and once
following. I also note that his published offset for NGC 4496 comes from
another later sweep where the galaxy was referred to 60 Virginis. That
observation is considerably more accurate than the ones recorded here, one of
which was apparently taken as the first observation of NGC 4496.
So, the conclusion is that NGC 4505 is indeed identical to NGC 4496.
=====
NGC 4508 is a double star at JH's position. He describes it as "vS, R, a * 13
with a burr." This is just how it appears on the POSS1 as the two images are
merged.
=====
NGC 4509. JH's position is just one minute of time too small. As far as I
can determine, this was first noted by Bigourdan who wrote, "This nebula, far
removed from the GC position ..." His measured position is correct. Reinmuth
flagged the corrected position, and Seyfert (yes, the same Seyfert) noted it
in his paper in HA 105, 219, 1937. This is where it was picked up later by
RC1. MCG and UGC have the correct position with no comment about the source
of the correction.
The galaxy itself is an odd little irregular galaxy with no trace of a
nucleus, but with many patches and knots over its face. The position I've
chosen is from GSC-A; it seems to represent the object as well as possible
given the lack of structure.
=====
NGC 4510. See NGC 4512.
=====
NGC 4512 is probably NGC 4521. Steve Gottlieb has questioned the identity of
NGC 4512 as given in the modern catalogues. CGCG, UGC, and MCG all point to
UGC 7700 at 12 32 32.9 +63 52 47 (J2000) as N4512. However, this object is
a pretty faint, low surface brightness spiral, and does not at all match JH's
description, "pB, R, psbM; 20[arcsec]".
Reinmuth (1926) suggested that this may be the same as NGC 4521. I looked at
the field, and at all the objects which John Herschel found in Sweep 412
(N2909, 3231, 3392, 3394, 3622, 3682, 4108, 4210, 4221, 4332, and 4441, as
well as 4512; there are no significant systematic offsets in Sir John's
positions from the true positions), and only see one other possible candidate
for N4512: N4510 (curiously, d'Arrest calls this a very small cluster; his
position is accurately on the galaxy, though). This is just 30 arcmin north
of JH's position, and a bit preceding. However, JH calls the object "pB", the
same as N4521 which is 1.2 mag brighter than N4510. Aside from that, though,
JH's description fits N4510 pretty well. But the magnitude difference makes
me cautious about accepting the identity. In addition, N4521 is closer to
JH's position for N4512. Everything considered, N4521 is the better match, so
is the object that I've adopted as N4512.
=====
NGC 4513 has a remarkably thin, and very beautiful, faint blue outer ring. It
could well serve as a prototype of the lenticular RINGED galaxies. It shows
well on the DSS2B image.
Coincidentally, it is just south of the other type of RING galaxy, in this
case, VII Zw 466 = A1229+66. The origin of the rings is completely different.
In the case of NGC 4513, gravitational resonances internal to the galaxy
generate the ring, while VII Zw 466 is probably the result of a nearly direct
collision between two galaxies, at least one of which is a spiral.
=====
NGC 4517 is also NGC 4437, which see.
=====
NGC 4520 = IC 799, which see.
=====
NGC 4521 is probably = NGC 4512 (which see).
=====
NGC 4526 is probably also NGC 4560 (which see), and figures peripherally in
the identification of M 91; see NGC 4579 for that.
=====
NGC 4529 may be UGC 7697, but the evidence is not very good. Here are my
comments in response to a question about this object from Steve Gottlieb in
October 1999.
Though WH has two observations, neither of his positions fall near any galaxy
he could have seen. His earlier position (which JH and Dreyer discount in
notes in the GC and NGC; more below) is 1m 20s east and 4.9 arcmin north of
UGC 7697, and 2m 39s east and 12.0 arcmin south of CGCG 129-006. His second
position is 1m 14s east and 20.5 arcmin north of UGC 7697, and 2m 23s east and
2.4 arcmin north of CGCG 129-006.
None of this inspires much confidence in WH's positions, especially given that
Dreyer quotes his first observation in the Papers: "Suspected a L, eF neb,
but tho' I looked at it a good while, I could not verify the suspicion, nor
could I convince myself that it was a deception." Dreyer than adds "P.D.
apparently only approximate," but the offset in the table is not marked with
a colon.
UGC 7697 is somewhat larger and brighter than CGCG 129-006, and has a slightly
higher surface brightness. So, if WH actually saw a galaxy in this area, I
think it is more likely that he saw UGC 7697.
All in all, however, the situation for making a clear identification for
NGC 4529 does not look good, hence the several question marks in the main
table.
Some additional comments: The NGC note is a slightly reworded version of JH's
GC note with the "erratum" in WH's published list merged in. Fortunately,
Dreyer decided to give WH's original data in the main table of his 1912
reprinting of WH's first list. Along with the second observation from 6 years
later in Dreyer's notes, we apparently have all the data WH collected.
Bigourdan's position, which Dreyer sites in support of WH's second
observation, is about 15 arcseconds off a faint star that Bigourdan must have
just barely seen, if, in fact, he saw anything at all.
Wolfgang's position makes his galaxy = MCG +04-30-003 = CGCG 129-006. I do
not know where the PGC's separate entry for NGC 4529 comes from, but the
position is closer to PGC 41463 = CGCG 129-006 than to anything else, so that
probably means that PGC 41482 = PGC 41463.
=====
NGC 4530 = 8 Canum Venaticorum (Beta CVn) is a star, though JH recorded a
"nebulous atmosphere" around it on four different nights. Dreyer notes in
the NGC that of the late 19th century observers, only Tempel suspected the
nebulosity, and even he was unsure about its existence.
There is no trace of nebulosity on modern photographs, and the star's spectrum
shows it to be a normal G0 V main sequence star with no strong emission lines.
Thus, it was probably just JH's bad luck to have seen the star on four poor
nights. Or his imagination may have been triggered three times by one poor
night. In any event, there is only a star here.
=====
NGC 4536. Note that the galaxy with this name included in UGC is actually an
incorrect reference to IC 3556, which is not NGC 4563. See both the other NGC
number and the IC number for more discussion.
=====
NGC 4537 is probably the same galaxy as NGC 4542. John Herschel's place for
N4542 is good, but Swift's place for N4537 is 49 seconds off in RA (his
declination is good, however). Swift's description fits the galaxy nicely,
including his note "nearly between two stars." In addition, this galaxy is
the brightest of the three in the area.
However, south-preceding N4542 is MCG +09-21-019 = CGCG 270-010. It, too,
could easily fit Swift's description: "eeF, S, R." It is also "nearly
between two stars." However, if this identification is correct, then Swift
made errors in both RA (30 seconds of time) and Dec (8.6 arcmin). The galaxy
is also considerably smaller and fainter than N4542, and would have been more
difficult to dig out.
Thus, I'm sticking with the idea, suggested by Steve Gottlieb, that N4537 is
most likely the same galaxy as N4542. The RNGC suggestion that it is MCG
+09-21-022 is very unlikely as this is the faintest galaxy in the group.
=====
NGC 4542. See NGC 4537.
=====
NGC 4544. See NGC 4740.
=====
NGC 4547 and 4549. These two galaxies are differently identified in CGCG and
MCG. William Herschel found both, measured the brighter south-preceding
galaxy twice, but the fainter north-following one just once. His positions
reduce to (equinox 1950)
N4547 12 32 32 +59 11
N4549 12 33 04 +59 15
These are not the positions used in the NGC, however. Those come from John
Herschel. Precessing his measurements gives (again for 1950.0)
N4547 12 32 26 +59 10.8
N4549 12 32 33 +59 12.4
At least his relative orientation of the objects is the same as his father's,
even though he places the two objects much closer together. And the positions
of NGC 4547 agree to within the errors of the Herschels' observations.
Checking the GSC and the Sky Survey shows five galaxies in the area. MCG
labels MCG +10-18-068 as N4547 and the preceding of the pair MCG +10-18-069
and -070 as N4549, while CGCG labels the pair as NGC 4547/9. The GSC
positions of these and the other two in the area are
MCG +10-18-068 12 32 16.24 +59 13 35.7
MCG +10-18-069 12 32 34.39 +59 11 31.4 = CGCG 293-030w = N4547
MCG +10-18-070 12 32 37.27 +59 11 16.6 = CGCG 293-030e
MCG +10-18-071 12 32 54.48 +59 19 23.4 = VII Zw 473
MCG +10-18-072 12 33 04.01 +59 13 29.4 = N4549:
There is also a faint star very close to JH's differential position from the
brightest of these five galaxies. It's my guess that this is the object he
mistook for the second of the two nebulae.
Looking at the descriptions that WH gave the objects, it seems likely to me
that the preceding of his two is identical with the brightest object in the
area, namely MCG +10-18-069. If so, then WH's relative and absolute positions
for the second object point exactly at MCG +10-18-072, making it N4549. The
galaxy is faint enough, however, that it ought to be checked at the eyepiece.
While I am reasonably sure about its identity as the second of the Herschels'
nebulae here, I've still flagged it with a colon.
=====
NGC 4548 is almost surely M 91, though M 58 = NGC 4579 (which see) has also
been suggested as M 91. Curiously, M 58 plays a role either way.
The story -- as far as I've traced it -- was first presented by William C.
Williams of Fort Worth, Texas in a letter to Sky and Telescope (December 1969
issue, page 12). Briefly, he suggests that Messier used M 89 = NGC 4552 as a
reference object to find offsets to M 91 -- but then mistakenly applied those
offsets to M 58 to come up with the position for M 91 that he lists. Going
through this exercise, Williams shows that Messier's position for M 91 can be
retrieved in just this way. Further, he suggests that applying the offset to
the correct comparison object (M 89) leads us to the correct object. In other
words, Messier misidentified his comparison object (if you've read more of
these notes, you'll know that he was not the last to do so!)
Let's repeat Williams's calculation with positions at the epoch of Messier's
observation. I'm using the facsimile of Messier's paper from the Connaissance
de temps for 1784 reproduced in "The Messier Album" by Mallas and Kreimer (Sky
Publishing, 1978); this gives the date of observation as 18 March 1781. With
the positions of the three relevant galaxies in hand for that equinox
(precessed from my selected positions for the objects), here is what we have:
Galaxy RA (B1781.21) Dec Notes
M 91 12 26 28 +14 57.1 From Messier's table
NGC 4548 12 24 24.6 +15 42 15 Precessed from J2000
NGC 4552 12 24 36.6 +13 45 51 Ditto; M 89
NGC 4579 12 26 40.4 +13 01 28 Ditto; M 58
The offsets of M 91 from NGC 4579 -- -12.4 seconds and +1d 55m 38s -- applied
to NGC 4552 yeilds 12 24 24.2, +15 41 29 which is very close to the position
for NGC 4548. The total V magnitude of NGC 4548, 10.2, is within range of
whatever telescope Messier was using that night (a similar galaxy M 98 = NGC
4192 has V_T = 10.1; Messier measured its position less than a month later on
13 April 1781). So, this is at least a plausible scenario, and is probably
the correct explanation for M 91 even though it requires several assumptions
about Messier's observing techniques (see above, and more at NGC 4579).
Owen Gingerich (in his introduction to "The Messier Album") suggests M 58
itself for M 91. That is almost certainly not correct; see NGC 4579 for that
story. Finally, see NGC 4571 for more on M 91.
=====
NGC 4549. See NGC 4547.
=====
NGC 4552 = M 89. See NGC 4548 and NGC 4579.
=====
NGC 4554 is another of Tempel's lost nebulae. He has only a brief note about
it in his fifth paper, calling it a very faint nebula 50 seconds preceding,
2.5 arcmin south of NGC 4567/8. This position is in the middle of an
extraordinarily empty field with nothing brighter than 19th magnitude for 2-3
arcmin in all directions.
Checking the signs of Tempel's offsets turned up nothing that matched in any
of the other three possible positions. There is a double star (noted in the
position table) that might be his object. It has a faint double galaxy about
an arcmin to the northwest, and an even fainter double star a bit further away
to the southeast -- these may have enhanced a nebulous appearance a bit.
However, adopting the brighter double as Tempel's object would require not
only changing the sign of the declination offset, but its size and the size
of the RA offset as well. So, I doubt very much that the double is Tempel's
intended object.
Until Tempel's original observing records can be examined for possible errors,
this object will have to remain "lost."
=====
NGC 4555 = IC 3545. Here is another case where Wolf made a mistake in
identifying an NGC object on one of his plates. He put the NGC number on a
faint object (this one about 2 arcmin south of the brighter galaxy) that could
not have been seen by the Herschels, and recorded the correct brighter object
as a new nebula. This led Dreyer to give it the IC number, apparently without
checking the descriptions too closely.
Wolf's error could have been a simple blunder, but I suspect that he simply
put too much faith in the NGC position without thinking too much about the
relative visibility of the objects.
This has left his object number 210 without either an NGC or IC number. For
lack of a better alternative, I've labeled it "NGC 4555A".
=====
NGC 4556. See NGC 4563 and IC 3556.
=====
NGC 4557 is a triple star. Bigourdan did not provide a precise micrometric
offset for this object, but his approximate offset with respect to NGC 4558
(-3 seconds of time, +2.8 arcmin), combined with his description ("Trace of
nebulosity which may be accompanied by a star...") clearly identifies the
triple as the object which he saw. The MCG and PGC identifications are wrong.
Wolf's identification in the Konigstuhl Nebel-List No. 4 is correct, where he
calls it stellar and places it between two stars (he obviously resolved the
triple while Bigourdan did not). The GSC includes 2 of the three stars, one
being the central one measured by Wolf. The position that I adopted some time
ago for N4557 is for this central star. Now (April 2015) with positions for
all three stars in hand, I've adopted my usual mean value.
=====
NGC 4558. Discovered by John Herschel north-following NGC 4556 (found by his
father), and given a position 6 seconds following and two arcmin south of the
true position, its identification is nonetheless clear as Dreyer gave
d'Arrest's micrometrically measured position more weight than Herschel's. The
NGC position is only 2 seconds and 0.8 arcmin from the true position. This
has not prevented its misidentification in MCG and PGC. MCG gives the name
NGC 4557 (which see) to it; PGC follows suit, and tries to save the number
4558 by applying it to IC 3556. Both catalogues are wrong. Wolf's
identification in the Konigstuhl Nebel-List No. 4 is correct.
=====
NGC 4559. IC 3550, 51, 52, 55, and 63 are HII regions in the arms of this
galaxy, found on a Heidelberg plate by Max Wolf. IC 3554 and 3564 are stars
superposed on the galaxy. See the IC numbers for a bit more information.
=====
NGC 4560 is probably NGC 4526 with a 2 minute error in the RA. Discovered by
WH, it was also observed by JH who gave a similar description. JH marked the
RA uncertain, however -- I wondered if he simply adopted the RA measured by
his father. So, I checked the sweep. The RA was apparently measured
normally, but no wire number is given. Instead, an illegible note appears in
the column usually devoted to the wire number. This same note appears in many
other of JH's observations. And in his "fair copy" of sweeps 1 to 107, the
letter M occurs often, apparently meaning the middle of the field. In that
case, the RA will indeed be approximate; and it does indeed appear in brackets
on the page in the sweep showing the final reduced place. The declination
reading is in also brackets, usually a sign that the measurement is uncertain,
or is taken from JH's "working list", prepared from WH's observations. The
reduced declination, however, is not marked as unusual in any way, so the
brackets in the observation column are (currently) mysterious, at least to me.
In any event, the declinations of N4526 and N4560 are the same, and the 2.0
minute RA difference is exact to within the errors.
Whatever happened, there is nothing in the Herschel's position for N4560. The
description agrees with the appearance of NGC 4526 with one exception -- N4526
is quite extended, while N4560 is described by both Herschel's as "round."
This is the main problem with the notion of the identity, but I find the exact
RA difference, combined with identical declinations, arguing pretty
compellingly for the identity.
=====
NGC 4561 = IC 3569. Found by WH on 27 April 1785, observed again by JH in two
sweeps, and rediscovered by Frost on a Harvard plate, there are no other
galaxies in the area as bright or as large as this. It is a peculiar
Magellanic irregular with two bright knots; one of these is a superimposed
star. These would have led to JH's seeing the object as mottled, and Frost's
description of two stars involved also fits.
Curiously, JH's mean position from his two observations is within a few arcsec
of the modern position from GSC, while Frost's photographic -- and presumeably
more accurate -- place is further off. It may be this that led both Frost and
Dreyer to include the galaxy in the second IC.
=====
NGC 4563. This was found by d'Arrest whose two micrometrically measured
positions are very good; the average is used in the NGC. CGCG still applied
the number to the wrong galaxy (IC 3556). Nilson copied this identification
into the UGC notes for NGC 4556 (= UGC 7765), but transposed two numbers so
that his identification is doubly incorrect: "N4536"! Wolf's identification
in the Konigstuhl Nebel-List No. 4 is correct.
The galaxy itself has two stars superposed on the west side. I had earlier
noted one of these as a possible companion when I looked at this on the DSS,
but on the more recent sky surveys, it is clearly a star.
=====
NGC 4567. See NGC 4554.
=====
NGC 4568. See NGC 4554.
=====
NGC 4569 = M 90. See NGC 4579.
=====
NGC 4571 = IC 3588. Found by WH, and reobserved by JH and d'A, the galaxy's
NGC position is pretty well determined. Nevertheless, Schwassmann measured
the 14th magnitude star superposed about an arcmin west of the nucleus and
called it N4571 in his 1902 survey of the Virgo Cluster. He also picked up
the galaxy itself at its correct position, and included it in his list as a
new nebula. Thus, the equality of the numbers.
This galaxy (also = GC 3113) has also occasionally been mentioned as a
possible candidate for M 91, first by Dreyer himself in the NGC. See his note
there where he equates NGC 4571 with GC 3120 = h1367 (more below) and actually
favors the idea the M 91 was a comet. He must have realized that NGC 4571 is
too faint (it has V_T = 11.3 in RC3) to have been seen by Messier. M 91 is
almost certainly NGC 4548; see that and NGC 4579 = M 58 for more.
JH was curious about M 91, too. He gave it a place in his 1833 catalogue (it
is h1367) using Messier's position and saying
A bright * 9m, and 2 or 3 smaller; close by the B star and sp it, is a small
well defined [sic] body which may be a close double star, and np it is also
a F neb. The place set down is that of Messier's 91st neb, but I do not
think this can be that object, whose existence even seems questionable.
In the GC (it is GC 3120), he is even more definite: "np this place is a F
neb; *not* [JH's italics] M. 91, whose existence ?."
The idea of M 91 as a comet was eventually taken up by Flammarion in his lists
of Messier's objects (Bull. Soc. astr. France, 31-35, 1917-21), and by Shapley
and Davis (PASP 29, 177, 1917; they refer back to NGC 4571). See also
Glyn Jones, "The Search for the Nebulae", Alpha Academic, 1975; and his
"Messier's Nebulae and Star Clusters", Cambridge, 1991 for more on M 91.
=====
NGC 4572 = CGCG 352-037 is a galaxy northwest of NGC 4589. It was seen by
both WH and JH, but Bigourdan's observation under "NGC 4572" actually refers
to a star a few arcmin southeast of the galaxy.
The galaxy has also been taken by some to be identical to IC 802 (which see).
But Bigourdan found that (also a star) the same night as his observation of
"NGC 4572", and his precise measurements of both show that they cannot be the
same.
=====
NGC 4577 is possibly WH's first observation of NGC 4591. He saw H III 13
(N4577) only once, and has this to say about it, "A minute before [the
transit of 24 Vir], I suspected a S. neb., but while I took out another piece
to examine it, I lost it again." Dreyer added the comment about the transit
of 24 Virginis, and also noted, "P.D. not taken, clouds. Not seen with
certainty by Bigourdan." N4591 is not the only galaxy in the area that WH
might have seen, but given his position, and the uncertainty in it, it is
perhaps the most likely.
There are some other problems with the observation that deserve mention,
though. First, the star name, 24 Virginis, is no longer used in the
catalogues, and I asked Brent Archinal to dig out the current identification.
The star is actually a duplicate entry for 5 Boo (apparently due to a
reduction error on Flamsteed's part), so does not exist in Virgo at all. That
being the case, there seem to me to be three explanations for Dreyer's comment
about the star: 1) the number is a typo; 2) Dreyer misread WH's observation;
or 3) WH misidentified the star. I think that a typo is unlikely -- the only
stars likely to be seen about the time that WH made the observations are R Vir
or 31 Vir. Getting a typo out of either of those would be difficult. I also
think that an error on Dreyer's part is unlikely -- his work on the NGC and
ICs is clear proof that he rarely made transcription errors. This leaves the
most likely explanation of an identification error by WH.
In any event, the comment about "24 Vir" does not help us much in pinning
down NGC 4577.
Other relevant thoughts and comments: WH's sweep covered a 2 degree wide
strip roughly between +5 deg and +7 deg (1950). The value of the polar
distance in the NGC comes from the GC, but JH does not indicate how he arrived
at it (or the description, "vF, vS"). If we take the polar distance to be
the same as WH's comparison star (11 Vir) for the RA, then the declination
would be 15 arcmin south of the GC and NGC value.
Unfortunately, WH has only one other nebula found the same night, II 26 (which
is probably = NGC 4430 and is discussed under NGC 4453). That is plagued by
similar problems, so offers little help in resolving the case of NGC 4577.
There are no galaxies in any of the places that come from WH's observations,
from GC/NGC, or from attempting to correct WH's RAs using the idea that H II
26 = NGC 4453 (which see) is actually NGC 4430. However, the approximate RA
that we do have, along with the constraints on the declination, point to
either NGC 4580 or NGC 4591 as probably being the object that WH saw. Since
N4580 is H I 124, and N4591 is III 504, the sparce description of N4577
strongly suggests that it is N4591.
Pending a different identification of "24 Vir," I'm going to take N4591 as
the second nebula that WH found on the night of 28 Jan 1784, though with
considerable doubt still attached.
-----
Checking CH's fair copy of the sweep in September 2016 turned up no additional
information. So, the NGC 4591 identity remains the most likely.
=====
NGC 4579 = M 58. This may also be M 91 according to Owen Gingerich in the
introduction to "The Messier Album" by Mallas and Kreimer (Sky Publishing,
1978, taken nearly word for word from his Sky and Telescope article in the
October 1960 issue, page 196). His reasoning goes like this: Messier picked
up all the really bright galaxies in the Virgo Cluster -- there are, according
to Gingerich, 13 that Messier saw (not including M 91). He goes on to say,
"Inspection of the Palomar Sky Survey photographs shows that Messier was
astonishingly successful in locating all the bright galaxies in this area,
while he invariably missed the fainter ones. There is simply no bright nebula
omitted by Messier that could conceivably be identified with M 91."
Well, not quite. First, I count 17 "bright" galaxies in the Virgo Cluster.
Here is a list with total visual magnitudes from RC3:
Messier NGC V_T Messier NGC V_T Messier NGC V_T
49 4472 8.4 84 4374 9.1 89 4552 9.8
58 4579 9.7 85 4382 9.1 90 4569 9.5
59 4621 9.6 86 4406 8.9 98 4192 10.1
60 4649 8.8 87 4486 8.6 99 4254 9.9
61 4303 9.7 88 4501 9.6 100 4321 9.4
-- 4526 9.8 91: 4548 10.2
Messier not only found 16 galaxies here, but he actually missed a 17th, NGC
4526 that he could have "easily" picked up just over a degree southeast of
M 49. I'm not going to suggest that NGC 4526 is the missing object -- it is
too far south to have figured in Messier's sweeping on the night of 18 March
1781. This assumes, of course, that Messier actually did sweep in the same
way that the Herschel's did, using his telescope essentially as a transit
instrument. Even Gingerich who examined Messier's extant records in Paris is
not sure exactly how Messier observed on this night, but also assumes
sweeping.
Let's also assume, following Gingerich's reasoning, that Messier does indeed
sweep along a north-south line, picking up stars and nebulae as they appear to
move westward across the sky. If this is the case, then the eight Virgo
galaxies found on 18 March (M 84 to M 91), listed in RA order in the
Connaissance des temps (reproduced in the Messier Album) were measured in that
order. M 91 is 40 seconds of time east and 34 arcminutes north of M 90 in the
list; there is, of course, nothing there. Gingerich suggests that M 58 is the
next bright galaxy in RA order in the Virgo Cluster within the zone swept up
by Messier that night. It's position differs from M 90's by 53 seconds east
and 1 degree 21 arcminutes south. Gingerich noticed that the difference in
declination between M 58 and Messier's position is about 2 degrees -- the
actual difference is 1 degree 55 arcminutes -- and suggested a simple digit
error of +2 degrees in Messier's published declination.
We can test this by asking how good are Messier's positions for the other
seven galaxies he measured that night. Here is the table, first for the
seven galaxies with the mean differences in RA and Dec shown with the
standard deviation and the mean error; next, with modern data for M 58 = NGC
4579 and for NGC 4548 to show the differences with Messier's position for
M 91:
Galaxy Messier's Position Modern Position Me - Mo
M NGC RA (B1781.21) Dec RA (B1781.21) Dec DelRA DelDec
s '
84 4374 12 14 01 +14 07.0 12 13 58 +14 06.1 +3 +0.9
85 4382 12 14 21 +19 24.4 12 14 21 +19 24.3 0 +0.1
86 4406 12 15 05 +14 09.9 12 15 06 +14 09.6 -1 +0.3
87 4486 12 19 48 +13 38.0 12 19 45 +13 36.1 +3 +1.9
88 4501 12 21 03 +15 37.9 12 20 56 +15 37.8 +7 +0.1
89 4552 12 24 38 +13 46.8 12 24 37 +13 45.9 +1 +0.9
90 4569 12 25 48 +14 22.8 12 25 47 +14 22.2 +1 +0.6
-----------
Mean Del +2.0 +0.69
Sigma1 +-2.5 +-0.59
SigmaN +-0.9 +-0.22
Galaxy Messier's Position Modern Position Me - Mo Notes
M NGC RA (B1781.21) Dec RA (B1781.21) Dec DelRA DelDec
s o '
-- 4579 -- -- 12 26 40 +13 01.5 (-12 +1 55.6) Actual pos.
91 (4579) 12 26 28 +14 57.1 (12 26 40 +15 01.5 -12 -4.4) N4579 + 2d
(91) 4548 (12 24 24 +15 41.5) 12 24 25 +15 42.3 -1 +0.8 M pos corr.
after WCW
The mean differences are +2s and +0.7 arcminutes, both significant at the
2-sigma level (compare to SigmaN).
[Incidentally, for a single observation on this night, this means that
Messier's positions are good to within 0.6 arcminutes in both coordinates,
considerably better than either of the Herschels managed, though that
comparison is hardly fair. We'll need to find Messier's standard deviation --
equivalent to Sigma1 in the first table above -- using ALL of his positions,
not just those from one night in a restricted area of the sky.]
This also means that if Gingerich is correct, the offsets for M 91 -- shown in
parentheses in the first two lines of the second table above -- are completely
at odds with Messier's measurements for the other galaxies. The 2-degree
error Gingerich suggests still leaves large negative differences in RA and Dec
for M 58, while the mean differences are positive by much smaller amounts.
So, I do not think that M 58 is M 91. The hypothesis put forward by William
C. Williams that it might be NGC 4548 (which see) strikes me as much more
plausible, given that the position for M 91 derived from his idea -- shown in
parentheses in the third line of the second table above -- is well within the
statistical errors of Messier's positions for the other seven galaxies
measured that night. In addition, NGC 4548 is very nearly identical in
brightness to M 98, so Messier could have seen it with whatever telescope he
was using then. I do agree with Gingerich, however, that Dreyer's ideas that
M 91 might be NGC 4571 (which see) or a comet are almost certainly not
correct.
=====
NGC 4580. See NGC 4577.
=====
NGC 4582 is a star found by Sidney Coolidge with the Harvard 15-inch
refractor. He has a micrometrically measured position that agrees well with
the modern positions. In common with many of the other "nebulae" discovered
in the 1850s and 1860s with this telescope, there is no nebulosity associated
with the star.
=====
NGC 4589. See NGC 4572.
=====
NGC 4591 may also be NGC 4577, which see.
=====
NGC 4593. See NGC 3679.
=====
NGC 4600 is probably not also NGC 4624, which see.
=====
NGC 4602. See NGC 3679.
=====
NGC 4604. SEGC is the source of this identification. However, since I have
not seen Peters's Copernicus articles, I cannot be sure that this is the
correct object. Since the NGC position is just 10 arcmin out (another digit
error), however, this identification is a good guess for the time being. Let
the RC3 stand as is for now.
-----
I was a bit chagrined to see that AH has a note, "Identified as a galaxy by H.
Corwin ... who indicates the NGC declination is in error by 10 degrees." This
of course, is wrong -- the NGC position is just 10 arcminutes out.
There is no trace of this in either of Peters's Copernicus papers, so this may
be a private communication to Dreyer. As Dreyer was co-editing Copernicus
with Copeland, Peters was already in contact with him, so this is a reasonable
assumption. It may not be right, but it is reasonable ... In any case, the
NGC position quoted in the big table is indeed just 10 arcminutes too far
north. I still favor a digit error in this case.
=====
NGC 4610 = NGC 4470. Dreyer, in his notes in the Scientific Papers, shows
convincingly that H II 19 = N4610 is the same galaxy as NGC 4470, and that WH
himself was at least aware that he had made a mistake in identifying one of
Messier's nebulae in the Virgo Cluster. Dreyer reproduces one of WH's
sketches of the I 7 and II 19 field -- it matches the appearance of M 49, an
accompanying star, and NGC 4470 perfectly.
=====
NGC 4611 = IC 805, which see.
=====
NGC 4618 = IC 3667, which see.
I've included the southeastern arm because Vorontsov-Velyaminov has it as one
of the components of his "interacting galaxy pair" VV 073. It is not a
separate galaxy, of course, but on the POSS1 prints, could perhaps be mistaken
for one.
=====
NGC 4621 = M 59. See NGC 4579.
=====
NGC 4624 = NGC 4665 = NGC 4664 (which also see). JH notes that the "RA [is]
ill-observed," but did not mark it uncertain. During the same sweep, he made
a one-degree error in the polar distance for NGC 4636, an error that he
himself suggested, and that Dreyer finally rectified for the NGC. Thus, NGC
4624 cannot be NGC 4636 as suggested by Reinmuth and adopted by RNGC.
Instead, it is most likely NGC 4665 which JH described as "B, pL" in two
other sweeps. This, and the appearance of the bright bar of the galaxy,
matches his terse description for N4624, "B, E." In addition, his
declination is correct for all three observations.
There is a faint possibility that N4624 is N4600, but JH's two observations of
that make it "F, S" in contrast to his note on N4624. In addition, the
declination of N4600 is off JH's measured dec for N4624.
=====
NGC 4625 = IC 3675, which see.
=====
NGC 4633 = IC 3688, which see. Also see NGC 4740.
=====
NGC 4634. See IC 3688 = NGC 4633.
=====
NGC 4636 is not NGC 4624, which see.
=====
NGC 4637 and NGC 4638. The brighter of the two galaxies now carrying these
numbers was found by WH (he actually found it twice, so it has two entries in
his catalogue). The fainter, a much smaller spiral of fairly low surface
brightness with a faint star superposed west of the nucleus, was seen only
once in 1854 by Lord Rosse (or his observer), who noted only a "Double
nebula; faint nebulosity connects them." Given this sparce description,
Dreyer assigned an approximate position to the fainter and called it NGC 4637,
giving NGC 4638 to WH's brighter object. He also added a note in the NGC
suggesting that Lord Rosse had actually seen M 60 (NGC 4649) and NGC 4647,
which are just 12 arcmin northeast. This would explain why no other observers
(aside from LdR and Herman Schultz) recorded the object as a double nebula.
Schultz's observation is an interesting one. He has an extensive note in
which he claims that the nebula is clearly double (in spite of relatively poor
seeing on the night of observation), nearly on the parallel, and with a star
of 10th magnitude north-preceding (which there indeed is; there is no such
star north-preceding N4647 and M 60). Like LdR, he says nothing about the
relative brightness of the objects, but records his surprise that neither of
the Herschel's noticed that the object was double and extended. Curiously, he
gives measurements (on two different nights) of only one of the nebulae,
though he specifically mentions that the micrometer wire, aligned with the
equator, nearly bisected both objects. His reduced position is that of NGC
4638, the brighter object.
In his Virgo Cluster survey, Schwassmann listed only one object here and
assigned it the first NGC number of the pair. His description fits the
brighter object, however, and he noted that the identity was uncertain and
that the object could be NGC 4638 instead. His position is peculiar, too: the
RA is that of the fainter eastern galaxy, while the declination is that of the
brighter western object. Remembering that Schwassmann's plate was taken with
a 6-inch lens, I suspect that the plate recorded only the brighter object and
that Schwassmann made a measurement or reduction error in his RA.
Dreyer, however, had only Schwassmann's entry to go on, not a modern sky
survey. So, he could not know about the potential problems in the Heidelberg
observation. Thus, he adopted Schwassmann's observation as applying to the
fainter object, and put a note in IC2 to that effect.
My own guess, without Schultz's confirmation of the duplicity of the object,
would have been that Dreyer was correct in his supposition about LdR having
misidentified the objects he observed in 1854. If this is the case, then NGC
4637 is a reobservation of NGC 4647 (found by JH) rather than the very faint
companion to NGC 4638. However, Schultz's observation seems to clearly point
not to M 60 and its companion, but to N4638 and its companion.
Still, LdR and Schultz could have seen the fainter object -- both have others
just as faint in their lists -- especially since it is enhanced by the
superposed star, so the "classic" numbering for this pair of galaxies is
still a possibility. I should note, too, that there has been some confusion
in the modern catalogues as to which number applies to which object. Dreyer
unfortunately confused the issue a bit with his IC2 note, and also with his
original numbering: JH had the fainter companion coming second in the GC.
Nevertheless, Dreyer clearly meant NGC 4638 to apply to WH's object, so that
is the identification I've adopted, leaving NGC 4637 as probably applying to
the faint companion -- or possibly to NGC 4647.
=====
NGC 4638 is probably also NGC 4667, which see. Also see NGC 4637.
=====
NGC 4644 has a faint companion which we now call "NGC 4644B" seen by Dreyer
in 1878 with LdR's 72-inch telescope. See the story in the "notngc" files.
=====
NGC 4646. Like NGC 4644, Dreyer found a companion, UGC 7905, to this galaxy,
too. The story is in the "notngc" files.
=====
NGC 4647. Is NGC 4637 (which see) possibly an observation of this object?
=====
NGC 4648. See NGC 4972 = NGC 4954.
=====
NGC 4649 = M 60. See NGC 4579 and NGC 4637.
=====
NGC 4650A and NGC 4650B = NGC 4661, which see.
=====
NGC 4652. There is no doubt about the identity of the galaxy that JH found;
his position and description "Not vF, pL, gbM. It is almost 6' dist np two
B sts 8 and 10m" are accurate.
The NGC comment "2 B sts 6' np" comes from LdR via Dreyer. Lord Rosse has
the position angles of the two stars 180 deg out. He also comments at the
beginning of the observation "Front view." This may have inverted the
field of the 72-inch from its normal orientation, leading LdR to the wrong
PAs.
=====
NGC 4661 has often been referred to in the literature as "NGC 4650B". At
first glance, we might think this alternate designation comes from deV's
"Stromlo 13" monograph on the southern Shapley-Ames galaxies. But there is no
trace of it there.
"NGC 4650B" does appear, however, in RC2. Tracing it back from there leads to
a paper in Astrophysics and Space Science (volume 19, page 387, 1972) by J. L.
Sersic and E. L. Aguero -- who refer to it only as "G7" in a southern chain of
galaxies. So, the awkward notation does indeed originate in RC2 (sigh). My
guess is that Antoinette noticed that it and "G5" are near NGC 4650 and,
following Gerard's example, put "NGC 4650A" on "G5" and "NGC 4650B" on "G7".
So how did everyone miss the original NGC number? The NGC declination is 17
arcmin in error, but is not marked as uncertain, nor is it truncated as many
of the NGC positions are. The only indication in GC that something is amiss
is the number of observations used: "1::". Otherwise, that, too, is given to
the usual full precision that JH adopted.
Going on back to the CGH observations, though, we find that JH has only one
observation of the galaxy in June of 1834, just a few months after his arrival
at the Cape. And the position there is given only to a full minute of time in
RA, and an arcminute in NPD. Both are marked with plus-minus signs, and JH
has no notes of explanation.
Given that, and the fact that "NGC 4650B" is the only galaxy around that JH
could have reasonably seen -- his object nearly identifies itself in spite of
the crude position.
=====
NGC 4663 = IC 811, which see.
=====
NGC 4664 = NGC 4665 = NGC 4624 (which see; that's another story). This is
another of WH's early discoveries with a large error in the position. There
is nothing at WH's given position. However, in this case, it is a simple
digit error in WH's recording or reduction. Dreyer correctly convinced
himself that it explains the missing NGC 4664 as a prediscovery observation of
NGC 4665 (= H I 142). The star 4.8 seconds preceding (mentioned in both of
WH's observations) is the clincher here, even if the exact 10 arcmin error in
Dec was not in itself enough.
=====
NGC 4665 = NGC 4624 = NGC 4664, both of which see.
=====
NGC 4667 is probably = NGC 4638 with a 2 minute 30 second error in RA. The
Dec's and descriptions are accordant, and there is nothing else in the area
that JH might have described as "B, S, R, psbM; 15 arcsec." So, while the
identity is a guess on my part, I think it is reasonable one.
-----
JH must have a mistake in his reduction as this object occurs in the sweep
(number 61 in Sweep 242) 4 minutes 31 seconds of time preceding NGC 4689. Yet
his reduced positions differ by only 2 minutes 32 seconds of time. As it
happens, NGC 4638 is almost exactly 5 minutes of time preceding NGC 4689,
much closer to JH's observed difference. Given the additional 30 second
error, I'm still not totally convinced that N4667 is another observation of
N4638, but it seems more likely than any other explanation.
=====
NGC 4669. This galaxy figures in the lack of an NGC entry for UGC 7905. See
that story in the "notngc" files.
=====
NGC 4676 = IC 819 and IC 820. WH has his object "much extended [in the]
meridian", while JH says "query if not bicentral". Both are correct.
When Rudolf Spitaler found the pair again in 1892, he saw and measured both
galaxies, so they have two IC numbers rather than just one as the NGC does.
Unfortunately, Spitaler has the pair only a minute-plus of time preceding his
comparison star -- the actual offsets are 2 minutes-plus.
The identity, however, is obvious. It was first suggested by Reinmuth, then
was picked up for RC1 and MCG.
=====
NGC 4678 = IC 824, which see.
=====
NGC 4686 is in the field of IC 3791 = NGC 4695. See the story under the IC
number for more.
=====
NGC 4689. See NGC 4752.
=====
NGC 4692 = NGC 4702, which see. Also see IC 823 for a different confusion.
=====
NGC 4695 = IC 3791, which see.
=====
NGC 4697. See NGC 3679.
=====
NGC 4702 = NGC 4692. D'Arrest has just one observation of NGC 4702 on 4 March
1867, calling it "Doubtless a very small, very much compressed cluster."
There is nothing at all in his place. Exactly a minute of time preceding,
though, is NGC 4692 which d'A has on two other nights, 16 March 1864 and 3
March 1867. Given the three or four nearby field stars around the galaxy, it
is possible that d'A could have believed that he had found a small cluster.
While the identity is not certain, I'm confident enough of it to have included
it in the position table without colons or question marks.
My thanks to Wolfgang who asked about this object.
=====
NGC 4705. See IC 825.
=====
NGC 4707 = DDO 150 has a superposed star near the center. From WH's terse
description, "S, stellar," it's obvious that he saw the star and just a bit of
the galaxy. So, I've assigned the position of the star to WH's "NGC 4707",
and provided another entry for "NGC 4707 gal" to represent the low surface
brightness dwarf galaxy that we now see behind the star.
=====
NGC 4711 = IC 3804, which see.
=====
NGC 4714. See NGC 4722 and 4723, and NGC 4802, below.
=====
NGC 4718 may be IC 825 (which see), but is probably not.
=====
NGC 4722 and 4723. These are two nebulae found by Tempel, described in his
fifth paper simply as "Following [GC] 3244 [NGC 4714] are two more small
class III nebulae which I have sketched, but have still not been able to
measure" (my translation of his note in German). Dreyer adopted the north
polar distance of N4714 and added a bit to its RA (with a plus-minus sign to
indicate the uncertainty) to arrive at an approximate position for Tempel's
two nebulae.
Bigourdan was the next to look for them, but his two measurements of "NGC
4722" fall in a blank region of the sky east of NGC 4714. His table is pretty
well scrambled at this point, with the declination of his comparison star
given only as "+27" and the footnote "Position deduced from that of the
nebula, given in the NGC." He has no errata, so just what his comparison
object actually was is still a mystery. He's a bit better for N4723 (N4714 is
the comparison object), but he only estimates the offset. The nearest object
to his estimated position for that is a faint star. In the end, he's no help
here. (One other curiosity: he claims, in the "Other Observer's" column that
N4722 was seen at Leander McCormick. But the object is not listed in any of
the LM papers on nebulae.)
He also found his 302nd new object, which became IC 3833, in the area. He
gave no indication, though, that it might be one of the NGC objects (see the
IC number for a bit more information about this).
That was left to Herbert Howe, who independently discovered and measured the
same galaxy that Bigourdan picked up. Howe suggested, in a roundabout way,
that it might be one of NGC 4722 or 4723. Howe's comment made it into the IC2
Notes, but Dreyer did not notice that Howe's position was identical to that
from Bigourdan for IC 3833. It was probably for this reason that MCG adopted
the identity "N4722 = I3833", a reasonable choice under the circumstances.
Finally, working on SEGC, I also adopted the MGC's identifications, though
without much thought. I did translate Tempel's note at that time, but of
course found it to be little help.
It's clear, though, that we do not (yet) know which nebulae Tempel found.
There are actually four galaxies following NGC 4714 that he might have seen.
The two brightest are IC 3833 and NGC 4748, the two closest to NGC 4714 are
MCG -02-33-024 and -026. It is tempting to simply put the NGC numbers on the
two closest and be done with it. But ... We need to find out if Tempel's
sketches still exist. These would clear up questions about not just these
two, but several other of his discoveries, too.
That was where things stood in the early 2000s when I last looked at these
objects. During my 2014-15 sweep for accurate positions, it finally occured
to me that Tempel described these as WH "class III" objects. This is the same
as NGC 4714, so we would not expect the two to be much fainter. This leads me
to suggest that Tempel's objects are indeed IC 3833 and NGC 4748, the
brightest of the objects "Following [NGC 4714]." We still need to see
Tempel's sketches, of course, but I have added entries in the position table
to reflect my latest thinking on this.
=====
NGC 4723. See NGC 4722.
=====
NGC 4724 is the fainter of a double galaxy seen by both Herschels. It figures
in the identification of NGC 4726, NGC 4740 = NGC 4727, and IC 3834, all of
which see.
=====
NGC 4726. There has been confusion over this number ever since Howe's first
note appeared in Volume 58 of the Monthly Notices for 1898 (page 515):
The NGC place of this nebula of Tempel's seems to be considerably out,
both in R.A. and declination. The correct position is 12h46m18s,
-13d40.6m.
This precesses to 12 48 55, -13 56.9 for B1950.0, and refers to IC 3834 (which
see). The confusion is understandable as Tempel's original note reads simply,
"Near the fine double nebula [GC] 3250-51 [NGC 4724-27], 4 arcmin further
north, is a fainter companion." Dreyer just took the average of the positions
for NGC 4724 and 4727, adopted the RA and subtracted 4 arcmin for the north
polar distance. This makes the declination very close to correct, but the RA
is off by about 9 seconds.
Tempel's nebula is a spindle galaxy; this is probably why Howe missed it. In
any case, he took the only other galaxy he could find in the area, the one we
now call IC 3834 (which is probably not NGC 4740, by the way; see the other
numbers for notes).
=====
NGC 4727 is almost certainly identical to NGC 4740. This is the brightest of
a group of galaxies, and the brighter of a close pair (NGC 4724 is the fainter
of the pair). It was seen by both Herschels, as well as by Tempel, Swift,
Bigourdan, and Howe. Considerable confusion in the NGC and IC numbers has
resulted. See NGC 4740 for the story, and also see NGC 4726 for one of
Tempel's nebulae that almost got away.
=====
NGC 4729 and NGC 4730. This problem arose because John Herschel's original
observations of 8 June 1834 yielded only very rough estimates of the positions
of the two galaxies (see his Results of Observations...at the Cape of Good
Hope... of 1847 for more information.) Inasmuch as the two galaxies were not
observed again until 1920, Dreyer had no choice but to use Herschel's rough
places when the NGC was prepared for publication in 1888.
Ron Buta came across this same problem some years ago during his
classification of galaxies on the Whiteoak PSS extension. In a letter of 3
Aug 1977, he suggested that the galaxies at 12 49 00.2 -40 51 33 (= ESO
323-G16, 1950 positions) and 12 49 14.0 -40 52 32 (= EU 323-G17) are N4729 and
N4730, respectively. Andris Lauberts came to the same conclusion at about the
same time when he was preparing ESO/Upps List VI. I entirely agree with their
suggestions as these are the two brightest and most easily seen objects
south-preceding NGC 4744 where Herschel noticed them.
The two galaxies are Vidal and Wickramasinghe's B and C, respectively. (By
the way, VW's D = N4744 and E = N4743). Jack Sulentic's incorrect RNGC
identifications refer to VW's "N3" and "N4", and Dawe et al are also wrong:
in their list (1970 positions), 12 50 24 -40 59 54 = N4729 and 12 50 38, -41
00 46 = N4730.
More confusion: under the designation HB 288 (more on that in a moment),
Sandage (Ap. J. 202, 563, 1975) gives the position of N4729, but the velocity
of N4730 (compare VW and Dawe et al). Unfortunately, the de Vaucouleurs and I
directly copied this mismatch into the Second Reference Catalogue (where the
data are under the single listing for "A1248-40") and Sandage simply repeated
his data in his redshift list in A.J. 83, 904, 1978.
Finally, the "HB" designations come from a series of papers by Knox-Shaw,
Gregory, and Madwar in the Helwan (formerly Khedivial) Observatory Bulletins
Nos. 9, 15, 21, 22, 30, and 38. N4729 - 30 were noted by Gregory in Bulletin
No. 22 as "Not found". However, among the (mostly!) new nebulae noted on the
Helwan plates, Gregory suggested that Helwan Bulletin nebulae Nos. 281, 282,
or 283 might be N4729 or N4730. De Vaucouleurs (in Commonwealth Obs. Memoirs
No. 13, his southern Shapley-Ames revision) concurs, but adds No. 288 as a
possibility. (He also confuses the nomenclature problem even further by using
"HB" for Harvard Bulletin! What a mess.) Actually, N4729 = Helwan Bulletin
288 and N4730 = HB 289.
=====
NGC 4730. See NGC 4729.
=====
NGC 4732. See IC 3791 = NGC 4695 where this number figures in one of Swift's
many mistaken identities.
=====
NGC 4736 = M 94. Wolf includes a good position for this in his fifth list,
but cites neither the Messier nor NGC numbers. He does have a footnote,
though, identifying the object as "A.G. Bonn 8688." The galaxy's nucleus is
indeed bright enough and small enough that it could be measured precisely and
included in the star catalogue.
=====
NGC 4740 = NGC 4727. Swift found this during his fourth year (1887 April 27)
of chasing down faint, "new" nebulae. He gives a position that is about 50
seconds of time west but only half an arcmin south of that for NGC 4727, the
brightest galaxy in the area. His description "pF, pS, R, mbM" fits N4727
better than any of the other three galaxies here, including IC 3834, taken by
nearly everyone (including me during my sweeping for SEGC) as NGC 4740.
Howe suggested that NGC 4740 is actually NGC 4726. He also published a short
note from Swift in one of his 1899 Monthly Notices in which Swift seems to
agree. But Tempel's observation of N4726 (which see) clearly rules this out
-- he places N4726 just four arcmin north of N4724 and N4727, a close pair
found by the Herschel's. With IC 3834 being another 45 seconds of time east,
it's extremely unlikely to be Tempel's galaxy.
Bigourdan did not find NGC 4740 at its NGC place, of course. I checked the
other nebulae found by Swift that night -- there were none, at least found by
LEWIS Swift. His son Edward, then a teenager, actually found four new nebulae
on the 27th: NGC 4544, 4633, 4969, and 5309. With the exception of NGC 5309
(which see), these all follow the nominal positions by about 18 seconds of
time, and are south by about 30 arcsec (NGC 5309, assuming we have the correct
galaxy, follows by 29 seconds, but has a 10 arcmin digit error putting it
south by 9 arcmin 10 arcsec).
NGC 4727 precedes the nominal position by 50 seconds, so does not agree with
the mean RA offset of Edward's nebulae. However, it is indeed 30 arcsec south
of Swift's position. (Did Lewis or Edward determine the positions for
Edward's discoveries? Lewis does not say in his papers, but because these
positions are no improvement over his father's, I would guess that Lewis did
them, or at least coached his son.)
I don't think we can make much of this comparison with the mean offsets,
though, because NGC 5309 also breaks the pattern, and because N4740 was the
only galaxy which Lewis Swift himself found that night.
However, of the four galaxies in the area, NGC 4727 -- by far -- comes closest
to fitting Swift's description. Thus, in spite of a few misgivings, I am
pretty well convinced that NGC 4740 is just another observation of N4727.
=====
NGC 4743. See NGC 4729.
=====
NGC 4744. See NGC 4729.
=====
NGC 4747 is the distorted companion of NGC 4725, one of the largest ringed
galaxies in the northern sky. The center of NGC 4747 is dominated by a
bright, bar-like structure defined by a row of several knots. I've taken the
position of the galaxy to be that of the brightest of these knots as seen on
the DSS2 infrared image. However, the SDSS position is centered on a compact
red knot (perhaps a superposed star?) that the 2MASS PSC also picked up in
addition to the brighter knot to the southwest. Perhaps coincidentally, the
2MASS XSC also uses this knot to define the position of the galaxy.
This red knot may be the nucleus of the galaxy, so I have given it a separate
entry "N4747 nuc?" in the position table. Unfortunately, I could not find a
spectrum of this particular object, so do not yet know if it is indeed the
nucleus, a superposed star, or just another knot in the galaxy's bar.
=====
NGC 4748 may also be NGC 4723, which see. Also see NGC 4722 and 4802.
-----
In November 2017, Courtney Seligman pointed out that there is virtually
nothing visible in the PanSTARRS image for the object Brian Skiff has measured
west of the two main components of the galaxy pair. On DSS2 red, blue, and
infrared plates, there appears to be a very faint loop of material roughly in
Skiff's position. There is also a faint star just a few arcseconds to the
northeast that may have been the "nucleus" of the image on the Lowell Pluto
Camera plate that Skiff measured.
However, these are all very faint features, so I suspect that the loop is
actually reinforced by a defect. I'll ask Brian to check the old plate.
=====
NGC 4752 may be CGCG 071-058. WH's description "vF, S, E, r" fits very well
-- but his position is 38 seconds off in RA, and 15 arcmin off in Dec. Dreyer
notes that Bigourdan did not find the galaxy, and gives an additional offset
from II 128 = N4689. That leads to a position that is within WH's
observational error of the one in his table, so there is apparently no large
error in his data collecting and reduction.
The fact that his description fits the CGCG galaxy so well, however, suggests
that there is an error somewhere in WH's position. But it is not apparent
from the information we have on the object, so I've put a question mark on the
identity.
=====
NGC 4759. See NGC 4776.
=====
NGC 4761. See NGC 4776.
=====
NGC 4764. This is another of the nebulae found by Tempel that has no position
given in his discovery paper in AN 2439. Either he or Dreyer concocted the
NGC position from what information he did give. See NGC 4776 for the sorting
out of this field for RC3 in the late 1980s.
=====
NGC 4768 and NGC 4769 are a star and a close double star, respectively. They
were found by Tempel while he was examining the field around NGC 4770, and his
only description of them is copied correctly into the NGC. He gives no
accurate positions, but the stars are a striking triplet just where he claims
to have seen them "preceding III 525 (N4770) on the parallel." There are no
galaxies or other stars that might fit, so the identities are pretty sure.
During an earlier sweep through the IC, I had misidentified the "northwestern"
star as a component of NGC 4769. This is wrong; NGC 4769 is the very close
double star (separation 3.3 arcsec at J2000, based on the UCAC positions) just
southeast of the single star to the northwest, which is, of course, NGC 4768.
=====
NGC 4769. See NGC 4768.
=====
NGC 4770. See NGC 4768.
=====
NGC 4772. See NGC 4910.
=====
NGC 4774 is one of the rare "ring galaxies", apparently a simple annular disk
of blue stars with no obvious nucleus. There is almost always a fairly normal
S0 galaxy nearby, however, and the suggestion is that it is either the
stripped nucleus of the original spiral galaxy, or the object which collided
with the spiral, completely disturpting it.
Others of this